What buffer/ buffer tube assembly is suggested for an AR 10/ .308? my father in law has an AR 10 that sends the BCG back into the stock and gets stuck. We have put an AR 10 buffer in the rifle but think it still has the AR15 spring. Do we just need to get an AR 10 spring or is the buffer tube itself supposed to be different? Whats a good site/brand to look at? What other things could be causing this issue? thanks.

Is it actually an AR10?  308 ARs are not standardized like an AR15 so you can't interchange parts.  What size buffer tube? Buffer? Is it a DPMS type rifle? If so, gen 1 or 2? PSA? S&W?

All full size 308 ARs can benefit greatly from Armalites carbine tube, operating spring, and H3 buffer if you're going for a standard, reliable setup.

You can use the Vltor A5 tube as well.

Both the 308 and standard carbine AR-15 receiver extension, will require a 308 buffer spring. If you're using the 308 buffer tube (3/4" longer then a AR-15 tube), you can use a AR-15 H2 or H3 buffer. If you're using a carbine AR-15 buffer tube for your Armalite AR-10, you will need a 308 carbine buffer, which is a little shorter then a carbine AR-15 buffer.

The difference between the AR10 rifle and the AR10 carbine buffer is the internal construction.  The rifle version is  ... just happen to have the page handy ... http://www.armalite.com/Categories.aspx?Category=287843a0-004a-46df-88bb-7f2ec6d594ce is longer at Overall Length: 5 3/16" Weight: 5.4 oz. and is all steel.  The ar10 carbine buffer is shorter Overall Length: 3 1/4" Weight: 5.4 oz. and is filled with 3 tungsten weights to keep the same moving mass in a shorter length so it has the same resistance to the recoil.



I swapped out the rifle length fixed buttstock for an adjustable carbine length,   much handier for differences in winter weight clothing vs. just shooting in a t-shirt.  Collapsed the assembly is now 2 inches shorter, or extended about the same length of pull as the rifle length assembly.



I used the same AR10 spring from the rifle and it is equally reliable and recoil (or lack of) is the same.  I like it!

Is it most likely that it just needs a stiffer spring? I think he bought an AR15 buffer kit, and then after trying to shoot it the first time just bought the shorter AR10 buffer. Throwing parts at it that aren't necessary gets expensive, do we need just a spring or spring and tube?

What is it, an Armalite?
Their AR10 collapsible stock buffer tube is longer than an AR15 and also uses a longer carbine AR10 buffer.
If he's using an AR15 tube, he needs Slash's Buffer.

First, you need to figure out what receiver extension he has (308 carbine tube or AR-15 carbine tube) then read my post above. If he's actually using a AR-15 carbine buffer tube, he needs a 308 carbine buffer with a 308 buffer spring. The spring can be bought from a lot of places like Brownells. The coils on the 308 spring is thinner then the AR-15 spring.