SBR with rifle buffer?

[cottonmouth]

I put my 7" RRA upper on my M16-A1 lower and it will not extract all the way, is this because of the rifle buffer and spring? How do I make it run?

J.B.

 

[Zak Smith]

I would recommend calling RRA and asking why their upper doesn't work.

Usually you can switch between a rifle stock/buffer/spring and a carbine stock/buffer/spring and it won't change how the upper works, unless the upper is screwed up in the first place.

 

[bkjeffrey]

it will not extract all the way

I would assume you mean short cycling? If so I would replace the rifle buffer with a car buffer.

As Zak said, you may need to play with different buffer and spring combos. 7" uppers can be picky. My 7" seemed to stovepipe and failed to extract leaving the case in the chamber with a standard buffer, it was cycling too violently thus ripping the extractor from the case and rebounding off the back of the buffer tube. I upgraded my extractor and sping, added a heavy carbine buffer and now its running great. Then I added a Spikes ST-T2 and its super smooth recoiling now as well.

 

[cottonmouth]

It runs great with my M4 style AR lower. This is the second M16-A1 I have tried and got the same result. It will pull the empty case almost all the way out then the next round double feeds. I figured buffer weight was the problem.

J.B.

 

[Zak Smith]

I would assume you mean short cycling? If so I would replace the rifle buffer with a car buffer.

You cannot use a carbine buffer with a rifle receiver extension ("buffer tube"). It will cause damage to the rifle.

 

[cottonmouth]

It's no doubt spring/buffer weight, I just tried another set out of diffrent rifle that has a shorter spring and it would shoot 2-3 rounds and crap out. Are there heavy weight rifle buffers?

J.B.

 

[bkjeffrey]

You cannot use a carbine buffer with a rifle receiver extension ("buffer tube").

Oops. I knew that.

Heavybuffers.com has heavy buffers for AR15 rifles with rifle buffer tubes. Custom weights available, but theres an 11 oz (vs 5.2oz standard rifle buffer weight) in stock for a pretty penny.