You've got a LWRC BCG in the rifle correct?
Wow, I just learned something! I've never messed with an AR10 before, but always figured the threads would be different or something to avoid a mix up.
OK. Let's take step back.
Please post a picture of the receiver extension, buffer and buffer spring. Also, please provide length measurements for each.
The Vltor A5 buffer tube and the magpul SR25 buffer tube, are interchangeable. In fact, one of the Vltor models is the AR10/A5SR. The primary difference between a standard buffer and a Vltor A5 buffer is that the A5 is longer. (there are other internal differences though) The reason an A5 buffer is longer, is to make up for the extra length of the receiver extension.
I learned something new, as well. When I replaced the commercial tube in my Bushmaster AR10 I just bought a mil spec AR15 extension tube. It works just fine, so ill leave it.
How? Does it use a shorter buffer?
Yes LWRC BCG
It was my understanding that AR15 stock kits work as long as you use the shorter style DPMS buffers/springs. The rifle length extensions are identical, and the Armalite/Vltor/SR25 extensions are used simply to accommodate standard sized AR15 buffers for collapsible stock options. Again, could be wrong, but that has been my understanding.
It is 2.5 inches long, while my AR15 buffer is 3.25 inches long. I never even checked it before now. All I did was replace the commercial lower receiver extension tube with a mil spec one. The crazy anal retentive side of me started worrying about the material strength of 6061 commercial tubes, so I swapped all my commercial tubes for mil spec. I had crazy itch, and this was the only way to scratch it.
That makes sense. I haven't fooled around with many AR10 variants, except for the SR25 and the Daniel Defense. Didn't realize that the Bushies and dpms used a shorter buffer. It honestly seems counter-intuitive that a larger caliber would use a smaller buffer. But thank you for the info!
