I need a bigger hammer

Ian

Well-Known Member
Got an M1A....with a scope. CASM makes the only scope mount worth having for the platform and I have a nice ffp scope on it along with a suppressor-mount muzzle brake and a Schuster adjustable gas plug. Magnificent weapon and it loves cast bullets but the whole package is nearly five feet long and weighs 13 pounds.

The Superlative Arms gas block would not vent sufficiently even when full-open with the 4320 load, but it was a lot better than nothing. When installing it I discovered that it has a dual function and will also restrict flow (nowhere did I see this in the ad hype and it doesn't come with instructions), so I worked it up from the fully-closed direction and got it working well at 23% open.

While screwing around with the gas block I was also collecting chronograph data and halfazz shooting another group. Ten shots stayed inside 1-5/8", not bad for zero load development. Predicted velocity was 2187 and actual was 2145 for a difference of 2%, not bad for throwing powder-coated bullets into the mix and and shooting the loads in a rifle with a big gas leak in the side of the barrel and a big muffler on the muzzle. The pc and gas port robs a little velocity and the can adds some back.

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popper

Well-Known Member
That works. Best I can find, 4320 burn rate is similar to 4895 but like a ball powder, meters great. I tried an H2 buffer in my BO pistol last time out, seems to tame recoil a tad but cases still come out @3. Yours still kicking them in front? My AR10 is stock DPMS rifle lower with carbine upper, AGB tames it a bit but really wasn't overgassed to begin. 4895 is my normal powder (41gr with 165 cast) so maybe your port was larger?
 
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Ian

Well-Known Member
Ejection pattern is now at 4:00, making a 2' pile about 11 feet away. The buffer is no longer whacking the end of the buffer tube, in fact I can't distinctly feel it at all once I got the gas cut back sufficiently.
 

Brad

Administrator
Staff member
You can easily alter ejection distance by cutting a coil or two off the ejector spring. Lots of HP competitors do so to keep the brass from flying as far. Fired prone my brass lands about a foot from me at roughly 1 o’clock.
 

Will

Well-Known Member
Groups are looking good so far Ian. This is definitely not helping me stay away from the AR 10 platform
 

Brad

Administrator
Staff member
Ignore him, he will eventually go fishing and leave you alone.


Or will he....
 

freebullet

Well-Known Member
Ain't gotta do nothin ya don't wanna.:)

Yes on fishing, but the lake will need to dethaw. Only fish from boats.
 

Rushcreek

Member
you have case and bore capacity on your side with the socum.
it's why the 8 mauser duplicates the 0-6 with the same pressure mapping.
you lose on the case end but gain more on the barrel end so the expansion ratio drops faster, allowing you to use all of the powder.

that is also why the 224 Valkery is going to go pretty much nowhere once the real world numbers hit the ears of other interested people.
nobody wants to lug around a 28+ inch barreled AR-15, which is what you need to get the 22-250 velocity's.
^^^Absolutely!^^^^