ar15 buffer question

[greyling22]

My ar is transforming. I'm swapping a midlength upper (lower had a carbine buffer tube) out for a RRA 20" predator upper (if it will ever ship). I have the regular carbine buffer and an h2 buffer. I'm trying to find out if the new upper will run on my existing lower/buffer combination.

My google-fu gives me an answer of "it might work fine, you'll have to try and see" can anybody give a firm answer?

 

[Zerodefect]

It'll work fine. But working fine deosn't mean it's correct. It's allways a good idea to do some tuning with buffer weights. You can get a H3 buffer and remove weights as needed.

I'll let the others chime in on exactly what they use, I just experiment.

Anyone have any recommendations for any carbine buffers for 18" rifle gas uppers as well?

 

[matrem]

I've ran 20" uppers on rifle buffers through H2 buffers with no problems.
Havn't tried one with H3.(guessing it would work though)
As mentioned , "tuning" the buffer weight to your rifle just makes the recoil easier to deal with.

 

[TonyAngel]

Just watch the ejection pattern. If it's throwing the brass forward (say a 2:00 position or farther forward) try a heavier buffer. If it's throwing the brass behind you (5:00 position or more) try a lighter buffer. You want about a 3 to 4:00 ejection.

 

[greyling22]

well that is really helpful tony. thanks.

 

[madcratebuilder]

As you can see from this buffer weight chart the 20" rifle upper is designed to operate with a 5.6oz buffer.

Rifle 5.2 oz
Carbine 3.0 oz
H buffer 3.8 oz
H2 buffer 4.6 oz
H3 buffer 5.6 oz
ST-T2= 4.3oz.
ST-T3= 5.4oz


I have rifle uppers run fine with H and H2 buffers.