Thank you

C

I am relatively new to loading 10 mm. I was looking at Longshot and the Hornady XTP bullet. That at least as I interpreted it, the 10 mm velocity's are only about 150 ft./s faster than the 40 Smith & Wesson, on the Hod Website...This is for near max load.I was under some general impression that 10 mm was considerably stronger than 40 Smith & Wesson I was expecting to see a different velocity difference at max load.

Does this ~150 FPS difference really translate into more impact oomph than it seems?

C

I have seen images of smileys. so it's this area, down at the bottom of the case where a smiley would occur due to incomplete chamber support, that should be measured in the process of working up loads. I did recall that 0.434 as one number of merit for overpressure indications.

I have a KKM barrel in the gun currently.

C

Shadow, thank you this is useful info. I have a 1"-0001 micrometer.

I typically set my crimp (de-belling) only enough to gauge well, then measure the mouth to double check I'm within a thou or so of spec.  In this "case" (har har) I'm at .4225 which I accepted.

Thank you I didn't realize that chambering from the breech wasn't a good idea.....

Where again on the case does one measure for pressure expansion....down on the web?  I cannot find that thread here now....which I saw earlier.

Lastly, one of my test rounds didn't chamber, and I discovered that some of the plating actually shaved and bunched up on the ogive. Never saw this with 9mm plated before...lead and coated, yes. And I thought I had belled the case enough, too. Is this a nuance issue with 10mm?  I have used oversized expanders on occasion with coated bullets in 9mm for select bullets. It was sometimes relevant to users if the U die also. Just curious if there is something I should be doing differently. I chose the Berry plated mainly because they were cheap, for practice...

C

Thank you. Great info....

Yes the crimp is now just a frogs hair from the ogive, but still on the bearing surface of the bullet.

The curious thing is that I also dropped it down directly into chamber and the G20 still won't go into battery.

They work now at 1.260...but not at 1.2750.  But for reasons I didn't expect. I figured it WOULD be a problem fitting in the magazine, from what I've read.  this bullet plunk tested far longer (1.30"+)and sits flush into the chamber like a factory round with barrel remove. I wasn't expecting the battery problem.  This is new Starline brass BTW.

Thx

I only bought a few as I work up some loads so i'll See how they work.

New to 10mm. For that matter new to Glocks also. I have a new G20 with new KKM barrel. I loaded some Berry's 180 gr flat top bullets. I understand that 1.250" is the rec max OAL. I always start with measuring the max OAL for my barrel by measuring the max length with 5 'push test' rounds using a fired case and bullet. I learned that with this bullet in the KKM, the max oal before the bullet would hang up is 1.360".

1.25" with this bullet puts the case mouth almost onto the ogive of the bullet (it's a truncated cone design). So I lengthend a round to 1.275" and assumed - because they plunked well at 1.360 - that this slight variation would not be a problem for loading.

But these 1.275" rounds will not go into battery. Even tho the bullet appears to drop into the removed barrel easily and fully, like factory ammo. I"m used to too long bullets 'hanging' on the lands but these didn't do so yet would not go into battery.   And they fit into the mag well, and even without the mag (dropping into the chamber through the breech) they don't go into battery.

When I shorten to 1.260" they all go into battery fine.

Can anyone recognize this issue and can explain it to me?  Or do I need to go back and test this again to make sure I didn't mess something up...Because if a round passes the plunk test, I have to assume it should go into battery normally, because the rim is at the same height from the breech face as the factory ammo that chambers fine..

Just ordered a KKM barrel. Don't have my Glock back from Robar yet but ready to make rounds otherwise.

1) Question: Looking at pics, it still looks like a portion of the case is not completely supported by even the KKM barrel. Or am I not interpreting this right?

Eventually I'd like to make 10mm loads just shy of max.

2) Question: Looking for advice on how to disposition my brass. I've read that if I see a full smile, toss the brass. That's my instinct anyway. I don't need to ration brass, won't be shooting that much of this.

3) Question: A bulged but un-smiled case can be resized and re-used provided it can be resized properly (fit in a case gauge)?

C

RDub01, thank you this is great.

What micrometer do you use?

What aftermarket barrels are popular for this goal?

Regards

C

I'm new to this forum. I load other pistol and some rifle calibers. Just bought my first 10mm, a Glock 20 SF that is having some grip reduction work done at Robar currently.  Really enjoy this pistol, Might get a G40 also.

I'd like to practice with some homemade ammo that replicates the energy of high end commercial ammo.   I see energies in the 650-700 ft-lb range for those products.

First, while it seems fine, just want to confirm that the G20 and G40 are, in your experience, fine guns for shooting those energies long term.

So far the official loading tables for most powders skirt just under that 700 ft-lb energy threshold....as I see so far.

I start low and work up using a chrono.

Do you have examples of loads they use that approximate the energy of these higher end hunting/defensive loads (Buffalo Bore, etc) and are still judged to be safe in a G20-40?

also, I prefer to use only plated or jacketed HP ammo...I shoot Berrys, Precision Delta, RMR, etc mostly.

ADDENDUM: Also, is the Gen 4 G20 stock barrel good enough (I read about chamber support issues) or should an aftermarket barrel be considered?

Thx

Clint