I have a thread in the Archives...See this thread if at all interested...for the whole discussion.

To make a long story short, I reloaded some LC brass with WSR primer, 24.3 Gr of TAC, 62Gr SS109 bullets.  

I initially fired them in my 11.5" barreled, wylde chamber mid-length gas with a A2 stock, rifle.  They would fail to extract and try to load another out of the mag, which of course is a catastrophic failure.  Sometimes it would extract but jam on the side of a new round, hardly getting it out of the magazine.

I wondered if it was my reloads and everyone on this forum chimed in with their opinions and help.  And I appreciate it.

The rifle in question when new, was sent back to Gunsmith because it wouldn't shoot the Wolf ammo, short stroked it, every round.  When I got it back it shot the Wolf just fine along with a few different surplus ammo Port, Guat, RORG, XM193, etc.  But when I tried my reloads, see above, the trouble started.

I finally got out with a couple of other AR15s and shot some of my reloads and they shoot rather well in my newest build.  16" mid-length  5.56 chamber, CAR stock.  But, again when I try to shoot these loads in the 11.5" barreled rifle it chokes.

So I have come to the conclusion that the 11.5: barreled rifle is indeed over gassed with these reloads.

So does anyone think a heavier buffer would slow this thing down.  Is there such a thing as a heavier buffer for a A2 stock??  I wonder if converting over to a CAR stock with a carbine buffer would slow it down?

Any comments, opinions appreciated.

You have a gas pressure and timing problem.

It had not clicked for me the first time I read through your thread that you are using an 11.5-inch barrel and a 5" flash hider (I am assuming a straight tube with no baffles and an open front end).

The XM-177, XM177E1, and XM177E2 "CAR-15" (10.5, 11.5, and 12.5-inch barrel) carbines used shorter gas tubes but the Colt XM-series flash/noise suppressor and the carbine buffer to correctly time extraction and ejection.

You've added a mid-length gas tube and a rifle buffer.  If you have an A1 or A2-style flash suppressor there's really not enough barrel length beyond the gas port for the system to build up enough pressure (over the short time the bullet has left before un-corking from the bore and dropping pressure) to push back and fully cycle your carrier group and a rifle buffer.

The rifle has a 5" permanent flash hider on it.  But still I think it would dump the gas as the bullet leaves the barrel bore.  Do you think a switch to a Carbine stock/buffer would cure it?

Here is a picture of the permanent flash hider.

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Sorry for the blurry phone picture.

I'm not sure that the midlength gas system is the proper length for a 11.5" barrel. But you said it works with other ammo types...

Try putting it on a lower with a carbine buffer system and see if that works...

Your reloads should be GTG i.e. they are not that hot, maybe hotter than the Wolf, but not as hot as the milsurplus stuff you have tried allready. I don't think overgasing is the problem.

Oh, just thought of this, the 5.5" flashhider isn't going to do anything to build up extra gas pressure, it's only function is to keep the barrel over 16". The XM177 et al. had a moderator that offered some sound reduction and some extra back pressure.

Too bad this upper didn't have a pistol lower, you could put on a Krink style brake like the Noveske PIG, and that might help...

A carbine buffer and receiver extension might help but you're still on a gas pressure and time curve.

If anything you are UNDER gassed with an 11.5 and mid-length gas tube.

You appear to have an early-90s pre-ban Eagle Arms carbine flash hider.  It will do nothing to help build back-pressure to cycle your carrier group (but it should make an 11.5 legal length and avoid an NFA violation).  Eagle Arms permanently mounted these on 11.5 - 12.5-inch barrels (carbine gas tube) to both stay legal and function:




Compare the distance from your gas port to the end of your barrel with a Colt 933 12.5" Commando:



If the carbine buffer and stock don't work you have a couple of options but you'll be spending money.  You could try to find an old AWC Hyperyne:



You could try a Noveske KX3;

you could try a full-blown suppressor;

or you could swap out for a 14.5 or 16-inch mid barrel.

Per Western's 5th Edition, 23.6 to 26.2 of TAC will produce up to 63,250 psi (.mil pressure) under an M855 62-grainer.  24.3 is still under their .223 data for 55,000 (SAAMI) under an M855.  As you wrote, your loads work in a 16 mid-length.

I can't thank you guys enough for the guidance.  I have a lot to think about.  

I think the first thing I'm going to try is switching the carbine lower onto the 11.5" upper to see what happens.

If the weather holds for tomorrow I might sneak out and shoot it.  But we are having Thanksgiving dinner with the kids coming in so might have to wait till Monday.