Both the DPMS SASS and the Armalite SASS use a standard A2 rifle receiver extension (buffer tube) that is found on any AR-15. There is no difference in the diameter of the A2 tubes.
The Commercial vs. Mil-spec receiver extension diameter differences only come in to play with carbine stocks. Additionally, the true Armalite AR-10 carbine receiver extensions are also a little longer than the standard AR-15 carbine tubes.
Yes the rifle is reported to me as a DPMS SASS. I will let the Guy know he should be OK.
His origional request was to shorten the LOP. I was unsure of the diameter thus unable to advise.
Anyone have any suggestions other than the Magpull? I think that would be a bit out of his price range right now.
Try a carbine style stock. I'd go with a magpul it's worth the money. If he's not picky though the dpms carbine 308 one comes with all the necessary parts for 69$. Some electrical tape on the tube and it was fairly firm although I was never completely satisfied with it.
Why shorten it? Usually people want more not less. I'm a little guy and a standard A2 fits me great.
Be sure if you start to change buffer tubes that you use a milspec or solid formed buffer tube some of the non-OEM tubes are welded and they don't stand up to the heavier recoil of the .308.
The buffer tubes on both fifle are the same dimension. Diameter and length. As you can see in the picture above the .308 colt carrier has a lerger diameter in the front where the bolt rides but reduces behind the gas key. This dimension is the same as the AR15.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: M25BeastShooter</div><div class="ubbcode-body">The buffer tubes on both fifle are the same dimension. Diameter and length. As you can see in the picture above the .308 colt carrier has a lerger diameter in the front where the bolt rides but reduces behind the gas key. This dimension is the same as the AR15.</div></div>
I just went to rip it apart and you're right, I thought they were different.