I have one that I bought from a builder and I’m having a problem. Shooting Hornady 168gr amax exclusively I think it’s overpasses but I’m not really sure. This is my first ar10 type rifle. The bcg seems to be cycling too far back and striking the receiver extension which is causing it to get chewed up a little. Also once in a while I’m having a failure to extract/ double feed. It’s causing the spent casing to get caught hanging out it the ejection port while the fresh round is chambered. Are these over gassing problems? How do I fix this? This gun is using all dpms internals
Buffer weight(s) adjustment maybe, try to slow down the BCG…?
Don’t listen to me thought, I am just guessing here… When it does cycle, where are the spent shells landing, 1:00 position, 5:00, somewhere in between?
1:00 position
That actually sounds undergassed.
Can you tell us what the specs are?
-buffer tube (length)
-buffer length and weight
-BCG
It sounds like something isn’t lined up right, the wrong size receiver extension/buffer or possibly a gas leak somewhere.
*also, is the receiver screw getting in the way? Mega receivers have a screw that screws up from the bottom of the receiver top ensure consistent lockup. That could be getting in the way pushing the upper receiver out of alignment.
It’s a carbine length buffer tube. Not sure of the weight of the buffer. But it’s a stock looking size buffer and it’s a dpms bcg I don’t see any gas leaks not sure about the screw. How much should it be sticking out. Buffer weighs 3.74 oz
I’m not an expert, but I agree that doesn’t look normal. You will get wear on the buffer face, but the BCG shouldn’t be hitting the receiver extension.
Is the green screw at the top of the picture the lower receiver screw I mentioned about earlier? Trying backing that off. I don’t even have mine installed.
ETA: post this over at the AR buliding/technical section… or have a MOD move it there. You’ll get more eyes, and experts looking at it then this subforum.
Is it just me or is that buffer retainer not properly caught?
Could be. Really hard to tell from the angle. I’m not sure what would be keeping it from flying out of it wasn’t properly assembled… from the angle it appears to not be properly captured by the receiver extension.
It’s in there. And isn’t shooting out. So I’m assuming it’s good
If you’re using a standard AR15-sized carbine receiver extension you should definitely get the CAR10 buffer and modified AR10 buffer spring from heavybuffers.com.
If your rifle is set up with a standard AR15-sized carbine buffer and spring as well as a standard AR15 carbine receiver extension, you can bet your rifle will have all sorts of problems…
It’s all dpms .308 parts.
It’s all dpms .308 parts
If you’re ejecting at 1 o’clock, the rifle is probably very over gassed. And the wear on the lower part of the receiver extension seems to indicate carrier tilt, probably caused by too strong a carrier impulse because of too much gas. The condition of fired brass will confirm if this is the case. The solution would be an adjustable gas block.
I have one from SLR Rifleworks, and a carbine buffer from Heavybuffers along with a standard 308 carbine buffer spring. My brass shows no pressure or early extraction signs now, and ejects at 3 o’clock.
Looks like I’m getting an adjustable gas block
The heavybuffers ur talkin about is that the standard weight buffer or xh
It was their standard buffer, 5.5 Oz IIRC. Not sure I would necessarily recommend it though, as it just feels like a whole lot of reciprocating mass. If I were you, I would get the adjustable gas block first and see if that solves it. If not, then start messing with adding weight, heavier springs etc.
Thanks
I might suggest that you take it back to the “builder” and get him to troubleshoot it…
That being said, should I be amazed at the number of people who are suggesting the OP throw parts at this problem before figuring out what the problem is?
I need this to be 100%. I want to start using it as a sass and get away from my bolt gun for a little while