With the help of some friends I have accumulated 5 different examples of 10mm Underwood Ammo loads and disected 4 of each. That's 20 total rounds disected where I made note of two measurements. Those were COL and powder charge weight. All round were clearly loaded with IMR 800-X.
One thing nice about disecting loads that contain 800-X is that you don't have to wonder if a couple grains of powder were stuck in the primer pocket or kinetic bullet puller toward getting an accurate weight measurement since the power flakes are very large and it's easy to tell if you've collected all of them (not that I still didn't make use of a flashlight to make sure).
All powder charges were weighed on two different scales. One being the Redding #2 beam scale, and the other being the Hornady Digital Bench Scale. COL was measured by both my dial and digital calipers.
After the noted bullet load is the listed range of COL I encountered in BLUE, and secondly the range of powder charge weight in RED.
UW 10mm 135gr Nosler = 1.249"-1.252", 11.4-11.7 grains
UW 10mm 155gr Gold Dot = 1.249"-1.254", 10.5-10.7 grains
UW 10mm 180gr Gold Dot = 1.249"-1.262", 9.6-9.7 grains
UW 10mm 180gr XTP = 1.250"-1.252", 9.4-9.6 grains
UW 10mm 200gr XTP = 1.253"-1.258", 9.2-9.4 grains
The results really make me wonder how much further they would have varied had I disected more than 4 rounds from each box of 50 total rounds. When I grabbed the rounds to disect from each box I didn't grab any together that were next to each other, but rather some distance apart from each other from each tray of a different load.
Someday I'll hopefully be able to get out and chronograph some of the rest of them from my G20. At this point what I can say is that I am now in no way surprised by others variance in their chronograph results, which does beg the question; How much are pressures varying?
Intercooler says Kevin says all loads are meant to be at 37,000 PSI. Clearly that isn't the case. The bigger question is in what way does the PSI trend, and does it matter?
What isn't in question is the sloppy load practice in at least the 10mm loads by Underwood.
Thanks.
Interesting. Who is getting these "variance in their chronograph results"?
My own opinion on it and take it for only that... a Glock isn't a suitable platform for consistent results. What pressure data did you get?
As for sloppy loads I am reading +/- .2 grains. Is that much with Cornflake size 800-X?
Thanks for the reporting.
Were these measured on an electronic scale? That could explain some of the variances...
It is a difficult powder to measure from a volume measure, hand weighing makes for better results.
For 800X, that doesn't look like "sloppy load practice" at all; it looks pretty darn good. +/- 0.1 gr is pretty acceptable, especially with a hard to meter powder like that. I'm a little surprised Underwood chose 800X, specifically because of it's poor metering, but looks like he's doing pretty well with it.
Quote from: Intercooler on November 06 2012 09:54:05 PM MST
My own opinion on it and take it for only that... a Glock isn't a suitable platform for consistent results.
Not trying to start an argument, but that's not true at all. I'm not a glock fanboy, but they are just as consistent as anything else, and the Glock 20 is one of the very few actually designed for the 10mm. People seem to forget that.
Thanks for the work Redline. Appreciate the data.
One thought for you in the process.
I like to weight each round assembled first, then weigh the components after disassembly. Sum of the parts should equal the whole. That helps me catch if anything gets spilled, lost, stuck, etc.
Just a thought.
One of my lifetime sayings is : You don't know more than the manufacturers!
In Glocks case we have had more than one spell it out in written print. I don't pretend to know more than they do.
Quote from: The_Shadow on November 07 2012 07:32:15 AM MST
Were these measured on an electronic scale?
Each of the 20 disected rounds was first measured on a Redding Model #2 Beam Scale, and then also on a Hornady Digital Bench Scale. Both scales agreed with each other in all 20 separate powder charges.
Quote from: sqlbullet on November 07 2012 01:04:32 PM MST
Thanks for the work Redline. Appreciate the data.
One thought for you in the process.
I like to weight each round assembled first, then weigh the components after disassembly. Sum of the parts should equal the whole. That helps me catch if anything gets spilled, lost, stuck, etc.
Just a thought.
I hear ya. But with 800-X in conjunction with a clean work area, it simply wasn't an issue. Not even a second guess.
Thanks REDLINE...Good to know! I actully like the performance of the 200XTP better with the 800X than the LongShot from my testing of 9.4 grains of each. While velocity was about equal, I think the pressure generated with the LongShot was higher. This was based off the SwampFox 1240 fps loadings where he used LongShot...he himself said he liked 800X better with the heavier bullets.
Quote from: Yondering on November 07 2012 10:53:56 AM MST
+/- 0.1 gr is pretty acceptable
That may or may not be true. We don't know what UW's target charge weight is for each load. So if the target powder charge weight is exactly in between what the results show, then yeah, argueably. If not...
Also, to my knowledge, my random sampling is the only random sampling ever shown, at least openly. It would be nice to see results from a couple of others too, even though I wouldn't hold my breath. The point is, my sample size isn't all that great.
I'm not as impressed as you are, and there are still other unknowns that keep us from understanding a full picture. No matter how we slice or attempt to discern what I've shown in this disection, we still also know that some UW 10mm 200XTP are capable of 1300fps, and there is something wrong there.
Either way, I'm glad I got to do some disecting to give us some idea of what's in'em and how much, variance or not.
Quote from: The_Shadow on November 07 2012 05:55:23 PM MST
I actully like the performance of the 200XTP better with the 800X than the LongShot from my testing of 9.4 grains of each.
Have you personally seen the same with any bullet lighter than 180gr?
Does 800-X make Longshot obsolete across the spectrum of bullet weights?
Quote from: Intercooler on November 07 2012 01:16:26 PM MST
One of my lifetime sayings is : You don't know more than the manufacturers!
Nor do we always know less than a manufactuer.
The most scrutinized ammo ever ;D
I haven't test with the lighter bullets but in conversations with Mike Willard of SwampFox he mentioned the lighter bullets achieved better results with LongShot than 800X. However he used LongShot across all bullet weights in his ammo.
IMO that title would go to Double Tap, more specifically their 10mm line. The key with Underwood is anything being in question or not, they are respected by the 10mm crowd as a whole (including me), even by those that simply aren't interested in ammo that powerful. Double Tap, specificly regarding 10mm, is not. So much so that they don't even get the respect of scrutiny anymore.
I never saw people going after DoubleTap or Buffalo Bore like Underwood. Even SwampFox didn't get much ink until later but not much in Kevin's ammo hasn't been tore down to almost the microscope level :o
I would be kind of flattered :D
Thanks for the info The_Shadow.
I had my first experience yesterday testing Underwood 200 XTP's which resulted in a very potentially dangerous outcome BUT it was fired in my CA89-10 (MP5 clone with a 8.85" barrel). I reported what happened to Kevin.
If you feel it is pertinent to your thread let me know and I'll post.
Not my thread but always looking to learn.
Don't know much about your firearm.
Yes please. Thanks in advance. The more information we can all gather together, the better toward understanding what is, what might be, and/or what to consider as a possibility gets, helping all of us to make the most informed and safe decisions possible.
The more details the better.
Quote from: Kwesi on November 07 2012 09:41:25 PM MST
I had my first experience yesterday testing Underwood 200 XTP's which resulted in a very potentially dangerous outcome BUT it was fired in my CA89-10 (MP5 clone with a 8.85" barrel). I reported what happened to Kevin.
If you feel it is pertinent to your thread let me know and I'll post.
Kwesi, If you don't mind, please elaborate as we are all here to understand and learn how any ammo is working or not working in a particular firearm.
I don't know if the MP5-10mm clone is using the same fluted barrel as the HK MP5, but if it does I suspect you saw the fluted chamber lines imprinted on the brass casings and possibly splits. Why do I say this? I have processed several thousand brass as shot from the MP5 10mm's, mostly Federal manufacture (gov. contract) and those conditions were seen as fire in those weapons. The Federal ammo is high pressure but the velocity is not as high as Underwood's.
I wanna hear too. I tend to think The Shadow nailed it. I can't imagine Underwood ammo getting along great with a fluted chamber. I haven't ever seen any splits in my CETME in 308, but rifle brass is very different than pistol brass.
Quote from: The_Shadow on November 08 2012 07:46:02 AM MST
Quote from: Kwesi on November 07 2012 09:41:25 PM MST
I had my first experience yesterday testing Underwood 200 XTP's which resulted in a very potentially dangerous outcome BUT it was fired in my CA89-10 (MP5 clone with a 8.85" barrel). I reported what happened to Kevin.
If you feel it is pertinent to your thread let me know and I'll post.
Kwesi, If you don't mind, please elaborate as we are all here to understand and learn how any ammo is working or not working in a particular firearm.
I don't know if the MP5-10mm clone is using the same fluted barrel as the HK MP5, but if it does I suspect you saw the fluted chamber lines imprinted on the brass casings and possibly splits. Why do I say this? I have processed several thousand brass as shot from the MP5 10mm's, mostly Federal manufacture (gov. contract) and those conditions were seen as fire in those weapons. The Federal ammo is high pressure but the velocity is not as high as Underwood's.
It has the same fluted barrel as the HK MP5. My 10mm cases in general sometimes have a black flute line but it has taken many loading before vertical case splits occur. None of the Underwood ammo had any splits. I will post the details in a few minutes and I'll try to post a pic of the remaining case that detonated out of battery.
In anticipation of my first hog hunt and based on the recommendations of more experienced hunters I purchased this Underwood Ammo. I loaded my CA89-10. I attached a E&W brass catcher and inserted an HK mag with the HI impulse LP installed. This is some of the most stout 10mm on the market & is loaded in Starline brass. Rated at 1250 FPS fired from a Glock pistol.
I chambered the 1st round then removed the mag as a safety precaution. Round one fired & sounded fine so I reinserted the mag and proceeded to fire 4 additional rounds on semi. No problems yet.
Time for full auto. I squeezed off a quick short burst of 4-5 rounds then I noticed a lot of smoke exiting the ejection port, the brass catcher was falling off AND my mag blew out onto the bench! I noticed two pieces of a brass case lying on the bench. One was the primer end and the other twisted shrapnel. The CA89 and myself were fine. I took her apart and found a live round not fully seated. After dislodging it I confirmed the barrel was clear. Reassembled her and attempted to resume SEMI ONLY but she would not go into battery.
When I got home I was expecting to find some small brass slivers in the flutes that prevented the round from fully seating. What I found was 50% of the length of the case (minus the primer end) stuck inside the flutes. I was fortunate to be able to tap it out.
I notified Kevin at Underwood and he was very concerned. He stated that they have only tested these rounds in a Glock barrel. He offered to replace it with ammo of my choice and pay the shipping. My guess is the FPS was closer to 1400 FPS.
Guess I'm going to use my 180 grain FMJ loads. Pic below of the case that detonated out of battery:
(http://i203.photobucket.com/albums/aa275/golfkwesi/P1020708.jpg)
(http://i203.photobucket.com/albums/aa275/golfkwesi/P1020707.jpg)
Thanks for sharing your experience in this situation and glad to hear you and the gun are OK.
Several things do come to mind when firing in full auto...
Chamber gets dirty...that's why the fluted design was added if I recall. However the flutes also lessens drag on the cases for easier extraction, if the softer Starline brass was used by Underwood and it was imprinting the cartridge case into the flutes, that may have add to the drag/friction factor. Due to the very high impulse and pressure of the Underwood ammo and the dynamic nature of the CA89-10, cartridge cases may have started extraction before pressures could drop to safer levels, thus holding the cartridges pressed to and/or into the flutes, causing the case heads to be ripped off during this ejection phase.
The picture appears that the casing was being pulled out of the chamber while under great pressure, as eveident of the rolled pressure formed ring from unsupported area ahead of the start ejection cut. Further cycling ripped the case head apart as a result of the weakened area which allowed the jets of high pressure combution gases to leak out. Leaving the forward segment (the thiness part) of casing stuck in the camber shows it was pressed tightly to the chamber walls, also tearing apart.
The Federal cases I have retrieved as shot from the MP5 10mm, many do split on their initial firing. I think their brass is somewhat harder/brittle, as not to expand as much in those applications, thus many crack and split length wise between the fluted chamber walls.
I am no expert...just some observations and my opinions, taking in the facts and dynamics of the situation.
BTW, I still kick myself in the ass for not buying one of those clones when opertunity knocked! Instead I left my money on the VLTOR Bren Ten ~~~~~"vaporware"~~~~~
My take is the same as The_shadow. Looks to me like the ammo separated and partially extracted while pressure was still high.
I would like to see some of the other fired cases. As kwesi mentioned, the chamber flute marks usually appear as burn marks. They do appear to be more metalllic in color on the case pictured. The chamber flutes are not only to make extraction easier as Shadow mentioned, but they will also provide for extraction in the event the extractor becomes broken or otherwise disabled.
My take on this is that the MP10 and clones are designed for FBI spec 10mm ammo.
BTW Kwesi, is not the first to have experienced issues in the MP-5 and Clones, I have read other post about issues.
I'm not sure exactly how much of 10mm casing is unsupported as chambered in the MP-5 10...looking at the cartridge in the chamber would indicate if there is some unsupported areas of concern.
One thing that did concern me with the fluted chambers is that it allows gasses to by pass because the chamber doesn't seal off like a normal chamber by the casing expanding to seal to the smooth chamber walls.
A buddy has the same gun and regularly shoots his loads of 165-175 grain that chrono 1500-1600. The CA89-10 with the Hi impulse locking piece installed should handle the Underwood ammo. My concern is that a round may have been loaded over spec causing dangerous pressure spike.
My 180 gr FMJ loads chrono'd @ 1232 with PP and 1262 with Longshot. I also chrono'd some factory Georgia Arms Canned Heat 165's @ 1360. All these were fired in the CA89-10.
I'll look closely at the other cases BUT I fired some of my loads that are mixed in. All are Starline.
I wish we knew what we'll never know. That is, what were the COL and powder charge weight in that one?
9 or 10 rounds were fired. It wasn't till the last round was set off that an issue occured. Coincidence? Maybe, maybe not.
I agree with 4949shooter in that I also would especially like to have a look at the other fired cases. This would allow for various other confirmations/insights.
The_Shadow, you mentioned indications toward an unsupported case head concern. I think there is a possibility there, but not enough information yet to make judgement.
Quote from: Kwesi on November 08 2012 11:46:02 AM MST
A buddy has the same gun and regularly shoots his loads of 165-175 grain that chrono 1500-1600. The CA89-10 with the Hi impulse locking piece installed should handle the Underwood ammo. My concern is that a round may have been loaded over spec causing dangerous pressure spike.
I wish we knew, but once they've been fired, there's little way to tell, outside of educated guesses.
QuoteI'll look closely at the other cases BUT I fired some of my loads that are mixed in. All are Starline.
That would be awesome if you could tell which ones were from Underwood and post pics. Maybe you can tell with some of them by a different residue being left behind inside the cases by the different powders used between UW using 800-X and you using what you did in the handloads?
One other thing I have thought of would be during the extereme cycling di a fresh round suffer a set back issue as it was being chambered? That would present why the issue occured like it did!
Did you contact Kevin about shooting it in a rifle? He doesn't have any ammo in 10mm classified as rifle ammo. I couldn't do ammo. People are going to shoot it out of anything including home-made firearms.
That's a good point The_Shadow about setback during chambering.
I will say though, I had a hard time pulling the 200 grain XTP loads with the kinetic bullet puller. I'm not sure if Kwesi was shooting those or a 200 grain FMJ load from UW. But back to pulling the 200XTP bullets, a few times I thought for sure I was going to break the kinetic bullet puller trying to get those bullets pulled. Multiple full force blows of the "hammer", over and over and over...
I could see a setback issue with a ligher bullet weight, but I'm not so sure with 200gr bullets. Plus, he has shot lighter bullet loads that should allow for easier setback, though it seems safe to say they were not up to the same load level of the UW loads.
Quote from: Intercooler on November 08 2012 12:19:04 PM MST
Did you contact Kevin about shooting it in a rifle? He doesn't have any ammo in 10mm classified as rifle ammo. I couldn't do ammo. People are going to shoot it out of anything including home-made firearms.
Yes. I discussed it prior to ordering. He thought it would be fine.
Quote from: REDLINE on November 08 2012 12:44:55 PM MST
That's a good point The_Shadow about setback during chambering.
I will say though, I had a hard time pulling the 200 grain XTP loads with the kinetic bullet puller. I'm not sure if Kwesi was shooting those or a 200 grain FMJ load from UW. But back to pulling the 200XTP bullets, a few times I thought for sure I was going to break the kinetic bullet puller trying to get those bullets pulled. Multiple full force blows of the "hammer", over and over and over...
I could see a setback issue with a ligher bullet weight, but I'm not so sure with 200gr bullets. Plus, he has shot lighter bullet loads that should allow for easier setback, though it seems safe to say they were not up to the same load level of the UW loads.
I was shooting the UW 200 XTP's.
You may want to talk to David Sneed he also had a carbine problem with an Underwood.
Quote from: The_Shadow on November 07 2012 06:29:45 PM MST
I haven't test with the lighter bullets but in conversations with Mike Willard of SwampFox he mentioned the lighter bullets achieved better results with LongShot than 800X. However he used LongShot across all bullet weights in his ammo.
I think the 155gr and lighter Swampfox loads were stoked with Win. AutoComp, not Longshot
Quote from: gofastman on November 08 2012 03:38:29 PM MST
Quote from: The_Shadow on November 07 2012 06:29:45 PM MST
I haven't test with the lighter bullets but in conversations with Mike Willard of SwampFox he mentioned the lighter bullets achieved better results with LongShot than 800X. However he used LongShot across all bullet weights in his ammo.
I think the 155gr and lighter Swampfox loads were stoked with Win. AutoComp, not Longshot
What information leads you to this assumption?
Here is some of what Mike shared on Glock Talk... Post 07-26-2011, 09:05 #33It depends on the burn rate. Slower powders burn over a longer period of time.
Comparing a shorter barrel to a longer barrel using, as an example, factory winchester silvertips. I can see that the pressure rises earlier and is topped out by the time the bulet moves about 3.5 inches.
In this case, a longer barrel will not affect the pressure but will achive a higher speed because it is continueing to act on the bullet for a longer time.
If you have a powder that is slower and the pressure is rising through practically the entire length of a 4.6 barrel if you add extra barrel length the prressure will rise higher. This is particularly true with the heavier bullets.
Using the silvertip bullet above as an example. I use a slower powder, one not optimized for a short barrel. If I look at it on a pressure barrel I can see it has not completely topped out at 4.6. My pressure barrel is 8 inches long.
This ammo is capable of 1350+ fps in a 4.6 barrel, but weel over 1400 in a 6 inch. The pressure rises to almost 37kpsi at teh 4.6 mark but is at 38kpsi+ at the 6 inch mark.
In the end, You have two choices when making ammo.
Make it for general use so that it will work pretty well in all firearms, but not great in any of them or you can be specific to the firearm/configuration and acheive greater results for that firearm but can have issues in others.
This was be seen in a recent case where a customer of mine was using my 200gr at 1325fps, that is optimized for a 4.6 barrel in a 6 inch barrel.
Post 08-05-2011, 13:18 #49I would add that the lighter the bullet the faster the powder can and should be, or more powder compression is needed(speeds up the burn rate) = shorter COL, or a slower powder and a magnum primer to speed the burn for light bullets, typically 135 or lower.
I find that longshot has has a slight advantage over 800-x on bullets in the middle of the weight range for 10mm, and 800-x is slightly better on 200gr and higher.
Quote from: Kwesi on November 08 2012 02:20:56 PM MST
I was shooting the UW 200 XTP's.
Thanks for clearing that up. It helps a lot toward understanding the bigger picture.
Thanks for posting that information The_Shadow.
The only idea I'm not buying into in what you quoted was "pressure is rising through practically the entire length of a 4.6 barrel." There is no way.
I don't believe that's true or possible without going to some slow burning rifle powder that wouldn't even work for 10mm Auto. For that to be the case I'ld expect any 4.6" platform (obviously a G20 in this case) to practially be a literal flame thrower immediately upon the bullet leaving the barrel, well beyond what anyone has ever seen from Blue Dot under virtually any circumstances.
So I also don't believe "The pressure rises to almost 37kpsi at the 4.6 mark but is at 38kpsi+ at the 6 inch mark." Not with any shotshell/pistol powder anyway. Not even H110 or 4227. There would simply have to be waaaaaaaaaaaay too much powder still burning for the pressure to continue to rise from 4.6" - 6" like he said.
Maybe I'm wrong, but I don't think so. Unless proof surfaces otherwise, I'm not buying it.
My understanding is that pressure spikes sometime in the bullet travel of within the first couple inches of barrel length and goes down from there. This is the first time I've seen it suggested otherwise. Like I said, without going to a much slower burning powder than any pistol powder, let alone 800-X or Longshot.
Redline, I agree 100%. From what I can tell, it looks like Swampfox was doing his own pressure testing, and based on his numbers, I think he messed up the time calculations. Could be just a decimal point in the wrong place, or something more. Regardless, pressure in any 10mm load is not increasing all the way until the bullet leaves the barrel. It just doesn't happen.
We've had this discussion on the Glocktalk forum too, about Mike's claim that longer barrels cause higher pressure. How he arrived at that conclusion I'm not completely sure, but I'd bet it wasn't by testing a long barrel and then shortening it and retesting. I think he was comparing different barrels with different lengths, which also had different internal dimensions.
Yeah, it just doesn't add up.
It's just plain outside of common sense, well, with some understanding of primer(s)/power(s) being lit up within a very small enclosed space acting upon a bullet then moving along some length of barrel, all the while not exploding the platform in the mean time. In this case, fast burning powders in short barrels within the realm of common handgun cartridges using common bullet weights per cartridge.
It was easy to determine which cases were UW and fired in the CA89-10 vs the G20 by comparing the firing pin marks on the primers. Every case has a case bulge (smiley?)! FWIW: I do not recall having these with my personal 180 gr FMJ loads. Anyways these are the photo's you requested:
(http://i203.photobucket.com/albums/aa275/golfkwesi/1FE1ABA3-33CB-48C4-B963-E90690060F56-100-00000000B196C9B9.jpg)
(http://i203.photobucket.com/albums/aa275/golfkwesi/67352F05-2EAA-4EBB-9FC8-707752197600-100-00000000BC7000E5.jpg)
Thanks Kwesi. From what I can make out in the picture, the striations in your Underwood brass don't seem to look any different than the spent brass from the thousands of rounds I had fired through my then issued P7M8.
I don't like those bulges, by the way.
Is it just soot, or does that case second from the bottom (first picture) have a crack?
Wow. Thanks very much for posting those pics. Definitely looks like a number of those were super close to doing the same as the one that did rupture.
Sure does appear from the casings that your platform has a relatively generous chamber size, maybe even with quite a bit of the case left unsupported at the case head?
Does the bolt face enshroud the case head? I guess I'm very curious to see how others discern what we see in those photos. It's just not a platform type that I really have any real knowledge of.
It looks like the second round down from the top has a bulge in the same area as what appears to be the crack in the other case.
Quote from: Yondering on November 08 2012 05:57:42 PM MST
Is it just soot, or does that case second from the bottom (first picture) have a crack?
It does appear that that case was going to split similarly to the one in the original posted pics.
Quote from: Yondering on November 08 2012 05:57:42 PM MST
Is it just soot, or does that case second from the bottom (first picture) have a crack?
I thought it was soot BUT upon closer inspection it IS a CRACK and it goes all the way around, a full 360*!
Quote from: REDLINE on November 08 2012 06:00:40 PM MST
Quote from: Yondering on November 08 2012 05:57:42 PM MST
Is it just soot, or does that case second from the bottom (first picture) have a crack?
It does appear that that case was going to split similarly to the one in the original posted pics.
You are right!
Quote from: 4949shooter on November 08 2012 05:54:30 PM MST
Thanks Kwesi. From what I can make out in the picture, the striations in your Underwood brass don't seem to look any different than the spent brass from the thousands of rounds I had fired through my then issued P7M8.
I don't like those bulges, by the way.
Why the bulges?
Quote from: Kwesi on November 08 2012 06:06:23 PM MST
Quote from: 4949shooter on November 08 2012 05:54:30 PM MST
Thanks Kwesi. From what I can make out in the picture, the striations in your Underwood brass don't seem to look any different than the spent brass from the thousands of rounds I had fired through my then issued P7M8.
I don't like those bulges, by the way.
Why the bulges?
Redline, Yondering, and the others would know more than me, but the bulges are a sign of excess pressure and / or lack of chamber support. It's a mystery as to why you have a bulge in the center of your brass though, as opposed to the bottom end where the chamber support would drop off.
Quote from: REDLINE on November 08 2012 05:59:05 PM MSTDoes the bolt face enshroud the case head?
Not sure I understand. If you google HK roller locked weapons you will find that the bolt head remains locked until the roller on each side retracts (safe pressure) and allows the bolt to travel rearward.
Quote from: 4949shooter on November 08 2012 06:09:06 PM MST
Quote from: Kwesi on November 08 2012 06:06:23 PM MST
Quote from: 4949shooter on November 08 2012 05:54:30 PM MST
Thanks Kwesi. From what I can make out in the picture, the striations in your Underwood brass don't seem to look any different than the spent brass from the thousands of rounds I had fired through my then issued P7M8.
I don't like those bulges, by the way.
Why the bulges?
Redline, Yondering, and the others would know more than me, but the bulges are a sign of excess pressure and / or lack of chamber support. It's a mystery as to why you have a bulge in the center of your brass though, as opposed to the bottom end where the chamber support would drop off.
Understood but the pressure must be much higher since I never have the bulge with my loads.
Well I don't know if this is possible, not being familiar with the weapon and all, but can you take a pic or two of how the rounds sits against or into the bolt face, and separately a round sitting in the chamber without the bolt up against it?
That would help me understand further a great deal. If not, that's cool too.
Lack of support. Throw a round in that puppy and take photo for us. Looks like the last 1/4" is fully unsupported.
Quote from: Kwesi on November 08 2012 06:10:02 PM MST
If you google HK roller locked weapons you will find that the bolt head remains locked until the roller on each side retracts (safe pressure) and allows the bolt to travel rearward.
I'll have to google that and come back with a better understanding.
Is this a correct depiction of your setup? If so, and if this very basic image is correct for your specific application and scenario, it would definitely seem your cases are being extracted before pressure drops to a safe level for the spent casing to be extracted (as has been suggested earlier by others). Well, with the pressure level of the UW 200XTP loads you were shooting anyway, compared to other lesser loads you also shot.
Otherwise it does seem like there is plenty of case support if this pic depicts anything close to your actual setup, aside from a generally loose chamber to begin with.
I got the image from http://commons.wikimedia.org/wiki/Category:Roller-delayed_blowback (http://commons.wikimedia.org/wiki/Category:Roller-delayed_blowback)
(http://upload.wikimedia.org/wikipedia/commons/0/0a/Roller_delayed_blowback_action.svg)
Thanks for the pictures Kwesi...It appears that there is a fair amount of unsupported casing as it sits in the chamber. Underwood's ammo is at the very upper end of performance as well as pressure. That MP clone being a longer barrel that the ammo was originally tested in could add to the subjected pressures to the casing.
The info from Swampfox/Mudrush was copied even with the mispellings. I agree that the peak pressure is spiked before the bullet moves from the casing, but in that short time it travels to the barrel opening, it is still quite high. I also mentioned about the type testing using the strain gauge on the exterior of a barrel chamber as opposed to those being used inside the chamber as SAAMI discussed in Publication 205.
I still stand on the premis that Star Line brass is soft (this is done with the purpose of reloading and reworking in mind) and at the upper limits of performance it will start to flow. I know that it was mentioned that Star Line provide brass to several other manufactures. Does the specs if internal case dimentions remain the same? Does their brass get other treatments to make them tougher? (they don't load to the levels of Underwood, SwampFox & Double Tap)
Look at what happens in the Delta Elites using the Underwood, they also needed a reduced loading to keep the brass from expanding and bulging so bad, this maybe what the MP clone will need as well with relation to timing and ejection.
Quote from: The_Shadow on November 08 2012 06:37:38 PM MST
I still stand on the premis that Star Line brass is soft...
Look at what happens in the Delta Elites using the Underwood, they also needed a reduced loading to keep the brass...
10mm brass on it's own, outside of a barrel chamber, is gonna handle what? 5000 PSI or so? Maybe less?
I'm not seeing that any available commercial 10mm brass by any manufactuer can be made hard enough or strong enough, within SAAMI specifications, to overcome the beyond-poor chamber support of a Colt Delta Elite.
And lets say Starline brass is the softest of any available. I'm not saying it's not. But by the same token, by how much? 1%? 20%? 50%? Enough that the brass brand is gonna make a noticeable difference? I'm having a hard time seeing it.
Am I missing what you're suggesting?
Do you disagree?
Sorry for the poor pics. Just could not get a better close-up:
(http://i203.photobucket.com/albums/aa275/golfkwesi/P1020714.jpg)
(http://i203.photobucket.com/albums/aa275/golfkwesi/P1020710.jpg)
Damn. That's a Delta x2! :o
What I am suggesting is that the stuff being loaded Underwood, SwampFox & Double Tap (of earlier years) were at the upper level of pressures & performance for most semiauto guns, they have had to back off the loads or change powders to eliminate the serious bulging as seen by many shooter with various guns. These same rounds as shot in barrels like the TC with heavy walled, tight chambers of full support can with stand more, also they don't have the dynamics of ejection phase while pressures are still present like the semiautos. As in this case, not all guns are equal...
This is why I load my own ammo, I control my own choices in every aspect of a load as related to my guns and the way they are set up to handle it.
Yea. You are going to need Delta-Lite or worse ammo in that puppy!
Quote from: Intercooler on November 08 2012 07:12:01 PM MST
Damn. That's a Delta x2! :o
That's kind of what I thought at first as well. But if you look at Redline's diagrams, the bolt should enshroud the case head when it locks into place.
Edit: Though I do agree, he will have to use something less powerful than Underwood 200 grain XTP. The Delta Elite load sounds like a good compromise.
Thanks again Kwesi, the pictures do tell a story of less chamber support and add to that the dynamics of things in motion during the ejection cycle, pulling the casing further out of the chamber, the expanding casing, also acting to push it self outward from the chamber all add up to the situation you have experienced.
Conclusion; I don't know enough about the HK system to say recoil system could be adjusted with different spring rates, therfore utilizing loads with slighltly less peak pressures provide you with safer operation.
I did just read you post over at GT where you decided on the Delta Elite tuned loading, sounds good. Please advise how this works from your gun when you get a chance! Best of luck! 8)
Quote from: The_Shadow on November 08 2012 06:37:38 PM MST
I also mentioned about the type testing using the strain gauge on the exterior of a barrel chamber as opposed to those being used inside the chamber as SAAMI discussed in Publication 205.
Can you provide a link to where you mentioned this? Was Swampfox using a strain gage setup?
Quote from: 4949shooter on November 08 2012 07:14:50 PM MST
The Delta Elite load sounds like a good compromise.
I agree. That setup doesn't look appealing by any measurement for full power 10mm loads. And it clearly you've proved it with the UW ammo you ran through it. Those pics are worth 1000 words, even if the bolt face shrouds the case head to some extent.
Redline, the remarks were made on GT, when XmmAuto, was buying the Pressure Trace system and the TC with a 10mm barrel to conduct pressure testing. As we discused the accuracy of such testing and calibration. He has since sold off the equipment and the TC pistol if I recall.
I also mentioned it here on this form as concern.
http://10mm-firearms.com/factory-10mm-ammo/10mm-ammo-history/ (http://10mm-firearms.com/factory-10mm-ammo/10mm-ammo-history/)
Quote from: The_Shadow on November 08 2012 07:28:19 PM MST
Thanks again Kwesi, the pictures do tell a story of less chamber support and add to that the dynamics of things in motion during the ejection cycle, pulling the casing further out of the chamber, the expanding casing, also acting to push it self outward from the chamber all add up to the situation you have experienced.
Conclusion; I don't know enough about the HK system to say recoil system could be adjusted with different spring rates, therfore utilizing loads with slighltly less peak pressures provide you with safer operation.
I did just read you post over at GT where you decided on the Delta Elite tuned loading, sounds good. Please advise how this works from your gun when you get a chance! Best of luck! 8)
The HK roller locked system does not utilize different recoil springs other than each caliber has a different spring. They utilize, in the 10mm and 40, two different locking pieces ( LP ). One is for low impulse ammo and the other is for high. I had the Hi LP installed which is what I also use for my 1200 FPS loads.
BTW: the Delta Elite rounds are a trade out and intended for my Delta Elite. I doubt I'll run any more UW in the CA89-10. She purrs out full auto with my loads. Remember the reason I purchased these were for my 1st hog hunt. I going to use my 180 loads. **** I forgot to mention that the UW was also for my G20 that I'll carry as a backup. I tested these with the OEM barrel and a KKM and had a few failure to feed's. I have a Wolf 22# spring and metal rod installed. I'm not prone to limp wristing but switched to my loads and had no issues at all. I did note that the OAL of UM were either 1.251 or 1.255 mostly whereas my are 1.255 - 1.260.
I was thinking of trying some original Black Talons - have about 8 loose rounds...
Quote from: The_Shadow on November 08 2012 07:52:26 PM MST
Redline, the remarks were made on GT, when XmmAuto, was buying the Pressure Trace system and the TC with a 10mm barrel to conduct pressure testing. As we discused the accuracy of such testing and calibration. He has since sold off the equipment and the TC pistol if I recall.
I also mentioned it here on this form as concern.
http://10mm-firearms.com/factory-10mm-ammo/10mm-ammo-history/ (http://10mm-firearms.com/factory-10mm-ammo/10mm-ammo-history/)
TYVM for the link.
My interest lies in what issues there are or aren't using a strain gage setup as opposed to the copper crusher system or the piezoelectric transducer system.
I did see at the link you provided in reply #21 where you said; "Using that system would be better than those which use the strain gauge wrapped around the out side of a barrel." But I saw no additional or other comments regarding the same, either to agree, discuss, or spell out where your thoughts are coming from on that.
So what I'm trying to find is any discussion or general writeup regarding, as you put it; "the accuracy of such testing and calibration" or the like, negatively toward the strain gage setup.
Can you give me anything toward that light or point me in a general direction?
Quote from: Kwesi on November 08 2012 08:09:30 PM MST
The HK roller locked system does not utilize different recoil springs other than each caliber has a different spring. They utilize, in the 10mm and 40, two different locking pieces ( LP ). One is for low impulse ammo and the other is for high. I had the Hi LP installed which is what I also use for my 1200 FPS loads.
If the high-impulse locking piece works correctly with your 180gr 1200 fps loads, I'd say you'd need an "extra high impulse" locking piece (if there were such a thing) for the Underwood loads. 180@1200 is relatively weak, compared to the Underwood stuff, or any "full power" loads, especially considering that 1200 fps is out of your 8.8" barrel. Just off-hand, Underwood 180's are probably at 1400+ from the same barrel?
Looks to me like that gun is just not designed to handle full power 10mm loads.
Quote from: Yondering on November 08 2012 08:36:04 PM MST
Quote from: Kwesi on November 08 2012 08:09:30 PM MST
The HK roller locked system does not utilize different recoil springs other than each caliber has a different spring. They utilize, in the 10mm and 40, two different locking pieces ( LP ). One is for low impulse ammo and the other is for high. I had the Hi LP installed which is what I also use for my 1200 FPS loads.
If the high-impulse locking piece works correctly with your 180gr 1200 fps loads, I'd say you'd need an "extra high impulse" locking piece (if there were such a thing) for the Underwood loads. 180@1200 is relatively weak, compared to the Underwood stuff, or any "full power" loads, especially considering that 1200 fps is out of your 8.8" barrel. Just off-hand, Underwood 180's are probably at 1400+ from the same barrel?
Looks to me like that gun is just not designed to handle full power 10mm loads.
I certainly understand your reasoning but my buddy has the exact same gun and runs 165-175's @ 1500+. Also to be more exact my loads of PP are 1232 and Longshot are 1262. I also fired Georgia Arms at 1360!
Thought you might want to see a pic of the gun we've been discussing:
(http://i203.photobucket.com/albums/aa275/golfkwesi/CA89-10RailStock.jpg)
(http://i203.photobucket.com/albums/aa275/golfkwesi/CA989-10SideFolder.jpg)
Quote from: Kwesi on November 08 2012 08:57:56 PM MST
I certainly understand your reasoning but my buddy has the exact same gun and runs 165-175's @ 1500+.
But what do those velocities equate to from 4.6" of barrel? I'm thinking much lower than you're thinking. Literally weak or just making it to "warm" by any decent 10mm standard. Probably around 1250 fps. So if that's the case, they are much less of a load than the UW 200XTP load.
Quote from: Kwesi on November 08 2012 09:01:37 PM MST
Thought you might want to see a pic of the gun we've been discussing:
Thanks for the pics. I was curious.
Quote from: REDLINE on November 08 2012 08:19:16 PM MST
Quote from: The_Shadow on November 08 2012 07:52:26 PM MST
Redline, the remarks were made on GT, when XmmAuto, was buying the Pressure Trace system and the TC with a 10mm barrel to conduct pressure testing. As we discused the accuracy of such testing and calibration. He has since sold off the equipment and the TC pistol if I recall.
I also mentioned it here on this form as concern.
http://10mm-firearms.com/factory-10mm-ammo/10mm-ammo-history/ (http://10mm-firearms.com/factory-10mm-ammo/10mm-ammo-history/)
TYVM for the link.
My interest lies in what issues there are or aren't using a strain gage setup as opposed to the copper crusher system or the piezoelectric transducer system.
I did see at the link you provided in reply #21 where you said; "Using that system would be better than those which use the strain gauge wrapped around the out side of a barrel." But I saw no additional or other comments regarding the same, either to agree, discuss, or spell out where your thoughts are coming from on that.
So what I'm trying to find is any discussion or general writeup regarding, as you put it; "the accuracy of such testing and calibration" or the like, negatively toward the strain gage setup.
Can you give me anything toward that light or point me in a general direction?
The second post is were I added my thoughts on the systems...
Here is something to consider...The pizoelectric transducer system employs the transducer flush mounted inside the chamber of the test barrel. Pressures developed by the expanding gases to the cartridge walls causing the transducer to deflect creating a measuerable electrical charge. This change is then converted to a pressure reading in psi.
Systems being sold are being used on the outside of the chamber of the test barrel.
The expanding cartridge is not directly acting upon the transducer as in the SAAMI testing. The preceeding line is why I think the results are skeptical for trying to measure outside the barrel. While the strain gauge outside the barrel system yields results, calibration and accuracy leave me second guessing, I could be wrong!
The other post #19 & #20 was descussing the Krieger test barrels and the internal strain gauge system like those used in actuall SAAMI testing. I have no way of knowing how Kevin Underwood test his ammo or what system he uses, he may have it outsourced or he may do it in house...he hasn't discussed this that I know of in the forums.
Thanks for elaborating.
Quote from: REDLINE on November 08 2012 09:03:08 PM MST
Quote from: Kwesi on November 08 2012 08:57:56 PM MST
I certainly understand your reasoning but my buddy has the exact same gun and runs 165-175's @ 1500+.
But what do those velocities equate to from 4.6" of barrel? I'm thinking much lower than you're thinking. Literally weak or just making it to "warm" by any decent 10mm standard. Probably around 1250 fps. So if that's the case, they are much less of a load than the UW 200XTP load.
I'm not sure I'm following your thought process. I agree that 1250-1300 is what his loads are in a 4.6" barrel. UW ammo is 1250 out of a standard Glock barrel. Your point? I updated the actual velocities above of the loads I fired: 1232, 1262 and 1360.
Quote from: Kwesi on November 08 2012 09:14:29 PM MST
Quote from: REDLINE on November 08 2012 09:03:08 PM MST
Quote from: Kwesi on November 08 2012 08:57:56 PM MST
I certainly understand your reasoning but my buddy has the exact same gun and runs 165-175's @ 1500+.
But what do those velocities equate to from 4.6" of barrel? I'm thinking much lower than you're thinking. Literally weak or just making it to "warm" by any decent 10mm standard. Probably around 1250 fps. So if that's the case, they are much less of a load than the UW 200XTP load.
I'm not sure I'm following you thought process. I agree that 1250-1300 is what his loads are in a 4.6" barrel. UW ammo is 1250 out of a standard Glock barrel. Your point? I updated the actual velocities above of the loads I fired: 1232, 1262 and 1360.
I'm just saying your buddy's loads of 165gr and 175gr bullets at +1500fps from 8.8" of barrel are weaker than the UW 200gr loads that hit 1250fps from a G20 4.6" barrel.
For example, a 165gr 10mm UW load rated for 1400fps would probably be doing around 1650fps from your friend's 8.8" barrel, and in my mind is weaker still weaker in terms of PSI developed than the UW 200XTP load rated for 1250fps from a G20, which should be doing 1450fps from an 8.8" barrel. And your buddy's 165gr load at +1500fps is weaker than either of those two UW loads.
And yes, you said; "My 180 gr FMJ loads chrono'd @ 1232 with PP and 1262 with Longshot. I also chrono'd some factory Georgia Arms Canned Heat 165's @ 1360. All these were fired in the CA89-10." What I'm saying about these is that they are outright weak based on the combination of your 8.8" barreled CA89-10 and the velocities you've shown compared to the UW 200gr XTP load.
So my point overall is that neither your buddy's loads at +1500fps or your PP and Longshot loads are anywhere near as powerful as the Underwood 10mm 200gr XTP load. And therefore I'm not surprised that your buddy's loads at +1500fps and your PP and Longshot loads are safe to shoot in your CA89-10, while the UW 200XTP load isn't.
Now I'm just hoping I haven't entirely missed what you were actually saying and/or asking. ;D
Quote from: The_Shadow on November 08 2012 09:05:33 PM MST
Quote from: REDLINE on November 08 2012 08:19:16 PM MST
Quote from: The_Shadow on November 08 2012 07:52:26 PM MST
Redline, the remarks were made on GT, when XmmAuto, was buying the Pressure Trace system and the TC with a 10mm barrel to conduct pressure testing. As we discused the accuracy of such testing and calibration. He has since sold off the equipment and the TC pistol if I recall.
I also mentioned it here on this form as concern.
http://10mm-firearms.com/factory-10mm-ammo/10mm-ammo-history/ (http://10mm-firearms.com/factory-10mm-ammo/10mm-ammo-history/)
TYVM for the link.
My interest lies in what issues there are or aren't using a strain gage setup as opposed to the copper crusher system or the piezoelectric transducer system.
I did see at the link you provided in reply #21 where you said; "Using that system would be better than those which use the strain gauge wrapped around the out side of a barrel." But I saw no additional or other comments regarding the same, either to agree, discuss, or spell out where your thoughts are coming from on that.
So what I'm trying to find is any discussion or general writeup regarding, as you put it; "the accuracy of such testing and calibration" or the like, negatively toward the strain gage setup.
Can you give me anything toward that light or point me in a general direction?
The second post is were I added my thoughts on the systems...
Here is something to consider...The pizoelectric transducer system employs the transducer flush mounted inside the chamber of the test barrel. Pressures developed by the expanding gases to the cartridge walls causing the transducer to deflect creating a measuerable electrical charge. This change is then converted to a pressure reading in psi.
Systems being sold are being used on the outside of the chamber of the test barrel. The expanding cartridge is not directly acting upon the transducer as in the SAAMI testing. The preceeding line is why I think the results are skeptical for trying to measure outside the barrel. While the strain gauge outside the barrel system yields results, calibration and accuracy leave me second guessing, I could be wrong!
The other post #19 & #20 was descussing the Krieger test barrels and the internal strain gauge system like those used in actuall SAAMI testing. I have no way of knowing how Kevin Underwood test his ammo or what system he uses, he may have it outsourced or he may do it in house...he hasn't discussed this that I know of in the forums.
Thanks for pointing out what you said in your second post. I missed that the first go around.
I guess I'm not sure there is an issue there or not, whether a piezoelectric transducer system measuring pressure from inside the chamber (let alone the copper crusher system) is actually any more accurate than a strain gage measuring stretch of steel based on a pressure level being contained by it from the outside of the chamber.
SAAMI's ANSI publication #205 doesn't say there is. They simply say they only recognize the copper crusher and piezoelectric transducer methods, but don't say for what reasoning either way. They don't comment one way or the other on the strain gage system measuring pressures from the outside of the barrel. Plus that publication was last copyrighted 19 years ago. That doesn't prove anything, I'm just saying.
Did a strain gage system even exist 19 years ago on the open market to average people like the one from RSI and Southwest Products?
I'm noting that in their literature they say; The strain gage was invented back in 1938 and are a common item in most laboratories. So the idea is to get strain readings of the outside barrel surface to the nearest millionth of an inch via a polymer material with very fine conductor loops on the surface that measure the stretch of the barrel steel by sensing changes in electrical resistance, that are then converted into pressure via a Wheatstone bridge producing output voltage directly proportional to the change in resistance of the strain gage, which is then passed through instrumentation amplifiers and an analog to digital converter where a microcontroller chipset sorts out what the end result in pressure in PSI is.
Well that's easy enough to understand for a caveman or sasquatch. ??? Okay, it's over my head. BTW, I got all that from here -
http://www.shootingsoftware.com/ftp/PTII-Help.pdf (http://www.shootingsoftware.com/ftp/PTII-Help.pdf)
I don't know, but I have yet to come across anything explaining why a strain gage setup is any less accurate than a piezoelectric transducer setup. And just because I haven't come across it doesn't mean it doesn't exist, so I may be wrong too. 8) I'll tell ya what though, if I could afford it I would have it, no different than having my chronograph. That is unless some information would surface showing the strain gage setup to be a literal waste of time and money. So far information like that doesn't seem to exist.
Quote from: REDLINE on November 08 2012 10:28:39 PM MST
Quote from: Kwesi on November 08 2012 09:14:29 PM MST
Quote from: REDLINE on November 08 2012 09:03:08 PM MST
Quote from: Kwesi on November 08 2012 08:57:56 PM MST
I certainly understand your reasoning but my buddy has the exact same gun and runs 165-175's @ 1500+.
But what do those velocities equate to from 4.6" of barrel? I'm thinking much lower than you're thinking. Literally weak or just making it to "warm" by any decent 10mm standard. Probably around 1250 fps. So if that's the case, they are much less of a load than the UW 200XTP load.
I'm not sure I'm following you thought process. I agree that 1250-1300 is what his loads are in a 4.6" barrel. UW ammo is 1250 out of a standard Glock barrel. Your point? I updated the actual velocities above of the loads I fired: 1232, 1262 and 1360.
I'm just saying your buddy's loads of 165gr and 175gr bullets at +1500fps from 8.8" of barrel are weaker than the UW 200gr loads that hit 1250fps from a G20 4.6" barrel.
For example, a 165gr 10mm UW load rated for 1400fps would probably be doing around 1650fps from your friend's 8.8" barrel, and in my mind is weaker still weaker in terms of PSI developed than the UW 200XTP load rated for 1250fps from a G20, which should be doing 1450fps from an 8.8" barrel. And your buddy's 165gr load at +1500fps is weaker than either of those two UW loads.
And yes, you said; "My 180 gr FMJ loads chrono'd @ 1232 with PP and 1262 with Longshot. I also chrono'd some factory Georgia Arms Canned Heat 165's @ 1360. All these were fired in the CA89-10." What I'm saying about these is that they are outright weak based on the combination of your 8.8" barreled CA89-10 and the velocities you've shown compared to the UW 200gr XTP load.
So my point overall is that neither your buddy's loads at +1500fps or your PP and Longshot loads are anywhere near as powerful as the Underwood 10mm 200gr XTP load. And therefore I'm not surprised that your buddy's loads at +1500fps and your PP and Longshot loads are safe to shoot in your CA89-10, while the UW 200XTP load isn't.
Now I'm just hoping I haven't entirely missed what you were actually saying and/or asking. ;D
Ok gotcha. One difference I realized is that it seems that you are assuming the velocity gain is 60+ per additional inch. I verified in my notes that the Georgia Arms Canned Heat 165's averaged 1245 out of my EAA Witness Limited which equates to about 30 additional FPS/inch. Not sure if this is relevant.
Thanks for everyone's input!
I have a CETME with a roller lock system that is identical in design to the system in this gun. I think the UW ammo, plus the way the chamber is cut, is setting up a perfect storm as it were.
The LP is calibrated for 10mm ammo's impulse, but as we all agree here, most 10mm ammo out there is really 40 S&W "+p" not really 10mm. I am going to assume the LP for 10mm is calibrated to the ammo made by the big boys for 10mm. This is generally 180 grain at 1150 to 1200 fps, not the 1350 to 1400 fps the 10mm can make. 40 S&W maxes out at about 1050 for 180 grain. All speeds for a 4.5" barrel.
So, if they make a different LP for 180@950 (factory 40) vs 180@1200 (factory 10mm) then you are definitely going to need a heavier LP for full power 10mm (180 @1400).
What happens is the lower mass LP allows the rollers to unlock before pressure has dropped, which causes adequate support to become inadequate support.
I think you will need a higher mass LP to get this to function with UW ammo.
Great information here ....
I got way into testing 800X years back and, more recently, testing Longshot at max loads also. In my experience, the 800X outperforms LS in velocity by a small (insignificant?) margin across all loadings. Accuracy is still undetermined. There are quite a few loads where LS really excels in accuracy, 9.2-9.4gr LS under a 180gr XTP is one of them.
Anyhow, I sitll have a bunch of my original bottle of 800X left. Keeping it for a rainy day.... but overall, I only use Longshot since 800X needs hand weighing. My next project is to do an accuracy workup at max velocity with 200gr XTP and WFNGC bullets, hand-weighing both the LS and 800X.... if there is any noticeable difference, I'll post it up, otherwise, I'll probably just carry on using my Longshot in the fuure. :)
Again, good info here, though. Kevin @ Underwood is doing a great job and I think his charge weights are spot-on where they should be.
Quote from: sqlbullet on November 09 2012 07:50:50 AM MST
I have a CETME with a roller lock system that is identical in design to the system in this gun. I think the UW ammo, plus the way the chamber is cut, is setting up a perfect storm as it were.
The LP is calibrated for 10mm ammo's impulse, but as we all agree here, most 10mm ammo out there is really 40 S&W "+p" not really 10mm. I am going to assume the LP for 10mm is calibrated to the ammo made by the big boys for 10mm. This is generally 180 grain at 1150 to 1200 fps, not the 1350 to 1400 fps the 10mm can make. 40 S&W maxes out at about 1050 for 180 grain. All speeds for a 4.5" barrel.
So, if they make a different LP for 180@950 (factory 40) vs 180@1200 (factory 10mm) then you are definitely going to need a heavier LP for full power 10mm (180 @1400).
What happens is the lower mass LP allows the rollers to unlock before pressure has dropped, which causes adequate support to become inadequate support.
I think you will need a higher mass LP to get this to function with UW ammo.
I believe you and the others are correct. Only problem: they don't make another LP for more potent ammo, the two choices are Hi or Lo LP's. OTOH: when I think back to when H&K developed the MP5 in 10mm the ammo was much more limited & thus less potent. I'm very happy using my weaker 180's and I would have used them for the hogs except the UW was recommended.
Well at least your gun wasn't damaged and more importantly, you weren't injured.
Quote from: 4949shooter on November 09 2012 10:53:35 AM MST
Well at least your gun wasn't damaged and more importantly, you weren't injured.
Amen to that. BTW: when I placed the order with Kevin for the XTP 200's I had not read his warning in red nor did he ask me if my gun had a ramp. If I had or if he had then the order would have never happened because the HK Roller locked weapons system has no barrel ramp. In the end I should have noticed that on his web site.
Quote from: Kwesi on November 09 2012 07:35:11 AM MST
Ok gotcha. One difference I realized is that it seems that you are assuming the velocity gain is 60+ per additional inch. I verified in my notes that the Georgia Arms Canned Heat 165's averaged 1245 out of my EAA Witness Limited which equates to about 30 additional FPS/inch. Not sure if this is relevant.
You are correct in my loose assumption, just than that I generally think about it as adding an additional 100fps per 2" of additional barrel length. And your are correct, it doesn't always work out that way depending on the specific 10mm Auto recipe being tested. It's simply the rule of thumb I use and most of the time works out pretty well in what I've seen. Again, certainly not always though.
Quote from: Kwesi on November 09 2012 08:34:51 AM MST
Only problem: they don't make another LP for more potent ammo, the two choices are Hi or Lo LP's.
This thought is over my head personally, but is there a possibility that someone with such know-how could modify the LP made for higher power loads to handle souped-up 10mm loads the same way there's a difference between the two LPs that already exist?
I expect it's probably a stupid thought, I just thought I'ld throw it out there anyway. :-\
This should put a new spin on some of the posts: HK lists specific factory ammo and which locking piece to use. These are recommended loads for the MP5 in full auto using the HI LP
Norma 170 gr. JHP @ 1461
Masters 150 gr. JHPN @ 1481
Hornady 155 gr. JHP @ 1445
Hornady 170 gr. JHP @ 1406
Winchester 175 gr. STHP @ 1377
I also find the following very interesting
Norma 200 gr FMJ @ 1195
Hornady Custom 200 gr FMJ @ 1124
BUT
PMC 170 gr JHP @ 1329 REQUIRES THE LO LP
I believe the key to this operating system has much to do with the "Impulse" of the load - don't have a clue how to measure!
Are those velocities out of your barrel length or a pistol?
Can't see Norma ever hitting that in any pistol.
Quote from: Kwesi on November 10 2012 11:29:37 AM MST
These are recommended loads for the MP5 in full auto using the HI LP.....
Gosh, hardly any of those loads exist anymore.
These are out of the MP5 barrel (same as mine). Many of those loads do not exist but as I stated earlier it's been many years since H&K developed the MP5-10 for the FBI. I've got some of those Norma and Win ST's but I'm happy with my FMJ loads. I believe it, while weak for the 10mm, will still do the job on the hogs and in semi. But if I'm wrong then we will go to the happy switch ;D
I guess I look at it that you're good to go anyway since with the barrel length of 8.8" you still get great velocity, even with heavy weight bullets. Kind of a win-win. Lower pressure loads with great velocity compared to what a common handgun platform is capable with any ammo.
Kwesi, you might want to try the standard Hornady 200 grain XTP load. Doc chrono'd 1050 fps out of his Glock 20 with these. With the velocity increase from your MP5-10 barrel, and a deep penetrating 200 grain XTP, this might be a good load for hogs without the concern of excess pressure.
Quote from: 4949shooter on November 11 2012 04:38:09 AM MST
Kwesi, you might want to try the standard Hornady 200 grain XTP load. Doc chrono'd 1050 fps out of his Glock 20 with these. With the velocity increase from your MP5-10 barrel, and a deep penetrating 200 grain XTP, this might be a good load for hogs without the concern of excess pressure.
Thanks!
I'm supprised no one pulled down a 165 gr loading to see the difference from the 155 grain. It was shown in a video that the 155 was pushed to 1500 fps if I recall...
Underwood 155 gr TMJ old load 1374 FPS @ 650 ft lbs
Underwood 155 gr TMJ new load 1551 FPS @ 828 ft lbs
Quote from: The_Shadow on November 11 2012 08:44:35 AM MST
I'm supprised no one pulled down a 165 gr loading to see the difference from the 155 grain.
Does anyone have an Underwood 10mm 165gr load(s) they would disect for us and post the findings?
Quote from: REDLINE on November 09 2012 06:51:16 PM MST
Quote from: Kwesi on November 09 2012 08:34:51 AM MST
Only problem: they don't make another LP for more potent ammo, the two choices are Hi or Lo LP's.
This thought is over my head personally, but is there a possibility that someone with such know-how could modify the LP made for higher power loads to handle souped-up 10mm loads the same way there's a difference between the two LPs that already exist?
I expect it's probably a stupid thought, I just thought I'ld throw it out there anyway. :-\
It's not a stupid thought at all. Some of the clone manufactures make a gun that was never produced by H&K. A Vector 53K is a good example (K stands for short). BTW: this is one of my favorite guns that is chambered in .223 and has a 5" barrel. They had to grind down a factory locking piece for this platform to function. The angle on each side of the LP is what determines the timing and cyclic rate on these platforms. That said I do not expect anyone will attempt this with the 10mm issue I've experienced. Good thought though!
Quote from: Kwesi on November 14 2012 07:47:19 AM MST
Quote from: REDLINE on November 09 2012 06:51:16 PM MST
Quote from: Kwesi on November 09 2012 08:34:51 AM MST
Only problem: they don't make another LP for more potent ammo, the two choices are Hi or Lo LP's.
This thought is over my head personally, but is there a possibility that someone with such know-how could modify the LP made for higher power loads to handle souped-up 10mm loads the same way there's a difference between the two LPs that already exist?
I expect it's probably a stupid thought, I just thought I'ld throw it out there anyway. :-\
It's not a stupid thought at all. Some of the clone manufactures make a gun that was never produced by H&K. A Vector 53K is a good example (K stands for short). BTW: this is one of my favorite guns that is chambered in .223 and has a 5" barrel. They had to grind down a factory locking piece for this platform to function. The angle on each side of the LP is what determines the timing and cyclic rate on these platforms. That said I do not expect anyone will attempt this with the 10mm issue I've experienced. Good thought though!
It's funny how I'm sometimes baffled by what's all available in the marketplace. That said, it then leaves me even further baffled by little things here and there that aren't. I'm quite sure you're not the only one out there who would take advantage of an LP designed to handle the likes of Underwood 10mm Auto power level ammo if one were to be made available.
never was impressed with Todd Bailey clones. Vector probably made the best CLONE you could get.
High pressure ammo in a fluted chamber probably not the best idea. HK didn't design the MP510mm for such loads...when it was designed (and short lived) it was during an era of subsonic speeds and deep penetration thinking.
So not only are you using ammo in a platform it really wasn't designed for...your using a CLONE (CA89 of all things) of the original platform.
Shadow,
Gotcha and corrected it.
Quote from: REDLINE on November 11 2012 10:48:44 AM MST
Quote from: The_Shadow on November 11 2012 08:44:35 AM MST
I'm supprised no one pulled down a 165 gr loading to see the difference from the 155 grain.
Does anyone have an Underwood 10mm 165gr load(s) they would disect for us and post the findings?
Are you guys still looking for the 165 gr. loads? I've got both the Underwood 165 GDHP and TMJ. I would be willing to sacrifice a few for the cause if needed.
Quote from: RMM on March 05 2013 08:53:12 AM MST
Quote from: REDLINE on November 11 2012 10:48:44 AM MST
Quote from: The_Shadow on November 11 2012 08:44:35 AM MST
I'm supprised no one pulled down a 165 gr loading to see the difference from the 155 grain.
Does anyone have an Underwood 10mm 165gr load(s) they would disect for us and post the findings?
Are you guys still looking for the 165 gr. loads? I've got both the Underwood 165 GDHP and TMJ. I would be willing to sacrifice a few for the cause if needed.
I think we're okay with the 165s. The_Shadow disected a Underwood 165gr Hornady XTP here - http://10mm-firearms.com/factory-10mm-ammo/underwood's-lineup-135155165180220/ (http://10mm-firearms.com/factory-10mm-ammo/underwood's-lineup-135155165180220/)
Since we've disected so many of the others along with the 165 XTP I feel we have a pretty good picture of what Underwood is doing overall, to the exent there's a good chance there wouldn't be much relevance going further.
Thanks for offer though! 8)
Intercooler did say that sample was from an older box of Underwood. I am wondering about QC as of late.
Good Point
My batches are from the end of January. They have the "Underwood" head stamp brass.
Maybe this weekend I'll pull a few down to satisfy my curiosity.
Richard
If it works out I'ld be interested in your findings. 8)
Someone with a pipeline to Underwood (looking at you IC :D) should put the bug in his ear to extend his website to include QC stats.
Stuff like % of loaded rounds verified by QC, and then variation reports on the QC findings....standard deviation and extreme spread on powder weights and cartridge overall length. If they perform tests on things like neck/crimp tension, that would be great to report too.
Seems like it should be a relatively simple add, and a huge differentiator.
I don't know anyone else that does it. Would that add to the cost of the ammo to have these QC steps done? I have no idea what's involved to do them.
If the dies don't change position, most stuff will be very close to tolerance, however brass being longer or shorter would affect crimp issues. Bullets that are either larger or smaller than proper diameter will have some affect on velocities and pressures.
The most important issue is powder measurement for consistency and uniformity, this along with all the other factors being in tolerance will deliver the most shot to shot repeatability.
Care needs to be taken to check that nothing is out of spec, such as loose dies and die parts, press parts too.
I would assume in their existing quality control, they remove X% of loaded rounds from the run, and measure head, case mouth, cartridge overall lenght, then pull the rounds and measure the powder charge. I would further assume that if in a given lot they have above a certain deviation from the expected values, the lot goes under additional scrutiny.
At least, I hope they do this, and I know that ATK does this at places like Lake City. My father-in-law is a retired Hercules/ATK employee. His entire career was spent as a safety specialist in rocket motor, propellant and explosive handling. He has visited Lake City a number of times to review their quality control and safety processes.
While I doubt a small shop can duplicate what ATK does, they can/should certainly mimic the basics of inspections of samples for each lot. Assuming they already perform these checks and record the results, I am only adding publishing the results. Cost to do that should be minimal.
Quote from: sqlbullet on March 07 2013 07:46:18 AM MST
I would assume in their existing quality control, they remove X% of loaded rounds from the run, and measure head, case mouth, cartridge overall lenght, then pull the rounds and measure the powder charge. I would further assume that if in a given lot they have above a certain deviation from the expected values, the lot goes under additional scrutiny.
While I doubt a small shop can duplicate what ATK does, they can/should certainly mimic the basics of inspections of samples for each lot. Assuming they already perform these checks and record the results, I am only adding publishing the results. Cost to do that should be minimal.
Seems reasonable.
I will get some pictures up later, but I pulled down (3) Underwood 10mm 165 GDHP cartridges.
All three measured 10.2 gr. powder on my calibrated digital scale. I don't have any 800x to compare it with, but it does look the same as the 800x I've seen in the pictures on this site. The flakes are much bigger than Longshot (which I do have).
RMM, did you see small tan flakes mixed in amogst the larger black flakes? The tan flakes are the identifier in IMR800X, but it is hard to mistake the huge round disk flakes... :o ;D
Quote from: RMM on March 16 2013 03:04:46 PM MDT
I will get some pictures up later, but I pulled down (3) Underwood 10mm 165 GDHP cartridges.
All three measured 10.2 gr. powder on my calibrated digital scale. I don't have any 800x to compare it with, but it does look the same as the 800x I've seen in the pictures on this site. The flakes are much bigger than Longshot (which I do have).
Seems logical being that the 155gr loads I disected ranged from 10.5-10.7 grains, and the 180gr loads I disected ranged from 9.4-9.7 grains. And of course they were also 800-X.
Quote from: The_Shadow on March 16 2013 06:07:22 PM MDT
RMM, did you see small tan flakes mixed in amogst the larger black flakes? The tan flakes are the identifier in IMR800X, but it is hard to mistake the huge round disk flakes... :o ;D
Yes indeed. Here are some pictures.
(http://www.smugmug.com/photos/i-ZXPDnqP/0/L/i-ZXPDnqP-L.jpg)
(http://www.smugmug.com/photos/i-Z3NhGdV/0/L/i-Z3NhGdV-L.jpg)
(http://www.smugmug.com/photos/i-g739FWz/0/L/i-g739FWz-L.jpg)
(http://www.smugmug.com/photos/i-JjCCfBq/0/M/i-JjCCfBq-M.jpg)
(http://www.smugmug.com/photos/i-K6s5T4J/0/M/i-K6s5T4J-M.jpg)
I will update this post with an average OAL. I can't remember where I wrote it down...
Yep! that's what we saw also, good job with the pictures!
Now put it back together and go shoot it!
Yep, it's official! 8)
I bought 20 boxes of Underwood's 180gr TMJ & inspected all of them. I measured 3 to 6 samples from each box for COL, a total sample of about 70 (didn't take an exact count). I found that the COL ranged from 1.243 to 1.247. Samples from 1 single box were never a greater range than .003. Measuring COL from 1 box of Federal American Eagle (5 samples) I found a variation of .004. I don't have the measurements in front of me at the moment.
I also measured fired cases from both the Underwood & the Federal. The were both the same at .433" at .125" above the extractor groove. These were fired out of my new Gen 4 Glock 20 with factory barrel & springs.
Quote from: DAVIDF on April 09 2013 10:40:59 AM MDT
I bought 20 boxes of Underwood's 180gr TMJ & inspected all of them.
Jeeze, I felt bad because I ordered TWO boxes when they only had like 32 boxes left! I just got them today, too.