358 Win AR-10 Reporting for Testing

[sqlbullet]

Well, nearly.



Sorry for the potato quality of the photo.  Just snapped it last night.  It isn't quite as complete as it looks.  It still needs a gas tube, bolt catch and either a muzzle device or thread protector on the muzzle.  Also, I have to drill, tap and install a set screw in the gas block to act as a gas regulator.

I have achieved my goal with weight.  The gun sits right now at 6lbs 8.4 oz:



The gas tube, bolt catch and set screw may push that up an ounce or two.  A heavy muzzle device would add 3-5 oz, which is why I am thinking maybe just some thread protector.  Even with a 5 oz muzzle device I would be under my 7 lb goal.

I have turned the necks on a half dozen brass and will get another 20-30 done tonight.  That will give me enough for a basic function test and some accuracy testing.

Build details:

Lower Receiver:
   TN Arms Co AR10
   Basic PSA MOE Lower Build Kit
   PSA AR10 six position Carbine buffer tube with 3 oz buffer
   Basic CAR-15 style stock
   VSeven titanium pivot and takedown pins

Upper Receiver:
   Fulton Armory Slick side cock upper receiver
   VSeven Titanium BCG
   KAK Industries 358 Win barrel 16"
   JSE Surplus Barrel Nut
   Online Metals 6061T6 Bare drawn 2"X0.035"X1.93" Tube 10-12" random length trimmed to 9.125" as a free float tube
   Fulton Armory "F" FSB
   Magpul MBUS rear sight
   BCM charging handle

Things I am likely to change.

PSA ships a longer buffer extension with a standard AR-15 carbine buffer.  This adds about 1" to the overall length of the lower.  I am pretty sure I am going to swap that for a standard AR-15 length buffer tube and a shorty AR-10 buffer.  An inch doesn't sound like a lot, but it sure does feel like alot in some circumstances.

I may also look at a different hand guard option.  My current choice was driven by weight and availability.  I started out with the JSE carbon fiber carbine length which weighed 5oz with the barrel nut.  But, since I have a mid length gas system, this left a good bit of gap.  The didn't have a mid-length carbon fiber option.  When it came it was kinda rinky, with them expecting the carbon fiber to be attached to the barrel nut with JB weld.   I was able to buy the aluminum tube online for $11, and it was a very tight press fit onto the barrel nut.  It still comes in at 5 oz.  I still have to torque it down, which may be fun.  With 11 oz to play with in the weight budget (5 oz handguard + 6 oz of gap after the gas tube and bolt catch are installed) I should be able to come up with a slim mid-length m-lock option that stays under 7lbs.  But I will run this one a bit and see.  The bare aluminum, utility, look is growing on me, so if it runs good I will probably just leave it be.

I need to swap out the buffer plate with something that works for a single point sling.  I have one on another AR I really like, just gotta remember where I got it.

And, of course, anything that prevents me from getting reliable function will have to be tweaked or replaced.  Hopefully that list will have no items!

I will update this thread as I add the last few parts, and provide range reports as I wring the gun out.  At this point I am really excited about this build.

[The_Shadow]

Interesting rifle sqlbullet...

[sqlbullet]

One last interesting note.

It will balance on the magazine with the stock extended and the MBUS rear sight down.  Put that rear sight up, and it will tip forward.

[sqlbullet]

I think I have solved my barrel torque dilemma.  I just ordered a Brownells 308 Receiver torque tool.  It goes through the upper receiver and engages the locking lugs in the barrel extension.  So, I can use my pipe vice, some leather to pad it's jaws, this torque tool and my 1/2" torque wrench and accurately torque it all down.

Beats my orginal plan which was to use a strap wrench and go by feel.

[oldman10mm]

I've been looking at/into a 358 'AR10' for a couple years now. I'm thinking along the lines of a 16" 'guide gun'. I discussed it with a gun shop in Sandusky Ohio. I picked up a 358 die set and been accumulating 358 brass from/at gun shows. I already load/shoot 35 Rem and want something in that 35 bore size in an autoloader.

[sqlbullet]

Guide gun was my goal with this gun.  Hence the target weight of under 7lbs.

I will warn you, this isn't the cheapest AR out there.  But, I am under $1500, which isn't bad at all for an AR-10.  The biggest keys to the weight were the TN arms lower and the titanium bolt carrier.  Those two components saved me well over 20 oz.

[oldman10mm]

That price range is what came up in discussions.

[sqlbullet]

The TN Arms lower saves you a good bit, but the titanium BCG is about 1/3 the cost of the whole project.

[oldman10mm]

What's your ammunition/reloading plans ?
Since 358Win is an 'undebore'(case capacity vs projectile bore) cartridge,the medium IMRs' of 3031,4895,4064 in a bolt action are the proper burn rate and the AR10,M14,M1A shooters seem to prefer 4064. I can't relate/comment on the other powders brands as I'm an IMRr'.

[sqlbullet]

I have about 20 lbs of WC846 so I am hoping the BLC2 loads I see will cycle the gun well.  I plan to shoot mainly heavy stuff, and have ordered and received a 310 grain "Thumper" mold from NOE with hollow point, cup point and flat point nose pins.

http://noebulletmolds.com/NV/product_info.php?cPath=35&products_id=2296&osCsid=rherta1vnhcm6bhjf577lrkdg3

When they get it back in stock I plan to order a 280 grain spire point mold from them too.

http://noebulletmolds.com/NV/product_info.php?cPath=35&products_id=317&osCsid=rherta1vnhcm6bhjf577lrkdg3

For brass I trimming down, sizing up and neck turning Lake City 7.62 blanks.  I have about 50 pieces finished.  I am in Europe this week, but hope to get some bullets cast next Saturday afternoon after my flight gets in, and maybe some loads to try on Sunday afternoon if the W's cooperate (weather and wife).

[oldman10mm]

Is converting 308/7.62 to 358 difficult ? How many steps ? I'm well stocked in 358 brass,so just curious.

[sqlbullet]

If you have native 308/762, just run it through an RCBS sizing die.  Easy breazy.  No harder than resizing a fired case.

Trim to length AFTER you size them up.  They shrink about .010" during the sizing process, so if you have trimmed them to 2.005", they will come out 1.995".

Word on the street is that brass formed this way MAY suffer from shorter neck life as the neck is thinned out a bit from stretching it up.  I can't find any hard data on this.

I am starting with fired 7.62 blanks.  They look like this:



The problem with these is the necks are far too thick after I get finished sizing and trimming them.  The neck walls should run about .012"-.015", and these run about .025".  So, I have to turn them.  Not a huge pain, but time consuming.  I need to try it on a drill press with the turning tool locked in a press vise.  That may speed things up a bit.  As it is, takes about 10-15 seconds additional per case turning them with a power drill and controlling the depth by eyeball.

[sqlbullet]

Made it out yesterday to do a basic function test.  Results were fabulous.



I ran only 20 rounds through her, all of Hornady 200 grain:

http://www.hornady.com/store/358-Win-200-gr-SP/

I had zero issues in function.  I was not shooting at paper targets, but had no issues hitting minute of clay pigeon or rock out to about 50 yards with iron sights.

Last night I cast up fifty 300 grain NOE HP bullets.  I will powder coat them tonight and then load of some test loads using WC846 for the next range outing.  That time I will stick an SWFA scope on her and try some real accuracy testing at 100 yards.  If all goes well, then a could hundred rounds will get loaded up for a true reliability test, and I will have my do it all guide gun.

[cwlongshot]

Great caliber choice!

The first "deer" rifle I bought myself was a Browning BLR 358! I have owned a Savage 99, Ruger 77, Re-chambered H&R and a re-barreled Model 7 Remington. Still have the Ruger & H&R. Shoudl have never sold the Remmy or the Browning.

The 35cal is one of my all time favorites in rifle cartridges. I have a bunch topping out at the 358 Norma mag.

I shoot a bunch of 225g Speer's in the H&R and 200g Hornady's in the Ruger.  I have been shooting the newer 200FTX and find it a nice game bullet. most FTX are fragile, while this one expands at lower velocities, i have pushed it past 2900 and it holds together. The old 200Hornady Spitzer is lil more fragile, shedding its core past 2500fps. The 225 Nosler accubond bullets are flat out awesome!

Best of luck with yours!

CW

[Captain O]

All that meat... (and no potatoes). 

Nice rifle, kid!