20" AR15 - A2 Stock vs M4 Carbine/Collapsible Stock

[LSUTiger]

I recently ordered a 20" AR15 Upper, A2 stock kit was out of stock. I currently have the parts to build a lower with the carbine/collapsible stock kit.

My question is there anyone who runs a 20" AR with the carbine buffer tube, buffer spring, buffer and collapsible stock?

Any do's and don'ts, advice?

[AJSully421]

Before I had a suppressor and had to go with a 16" barrel, I had a 20" with a collapsible stock. It needed a H buffer, but everything comes with that now.

[Bitter Clinger]

Running a stock 20" Colt 1:9 upper on a dead stock Colt LE 6920 carbine lower, not a single part change required and not a single problem. 3-9 Explore Optics tactical (railed) scope, good so far out to 600 yards. Credit to AndyC for pic.

[LSUTiger]

Ignoring differences in carbine vs rifle spring resistance, from my research, general consensus seems to be that when using a 20" Rifle Upper with rifle gas system on a carbine lower/buffer tube that H2 carbine buffer 4.6 oz or H3 carbine buffer 5.5 oz or or a damage industries H6 carbine buffer 5.0 oz. is optimal to get the same performance as a rifle buffer 5.0 oz.

The main difference between the H3 and H6 is the H3 has 3 weights and the H6 has 6 weights. The 6 weights are supposed to help further eliminate the bolt bounce back somehow.

FYI the H6 buffer is what the USMC has adopted when running a 20" Rifle on a carbine tube lower. I didn't know they did that. I thought is was just those crazy Canadians with the C7/C8 variants.

[glazer1972]

I had a LMT Lower with Sopmod on the twenty I had. I have since went to an 18" hbar and am still running the same lower. No changes at all in the lower.

[The Annoyed Man]

I recently ordered a 20" AR15 Upper, A2 stock kit was out of stock. I currently have the parts to build a lower with the carbine/collapsible stock kit.

My question is there anyone who runs a 20" AR with the carbine buffer tube, buffer spring, buffer and collapsible stock?

Any do's and don'ts, advice?

I have an 18" AR15 in a DMR/SPR configuration that I run with a collapsible stock, but it isn't the cheap carbine M4 stock. I use a VLTOR EMOD stock.

This is the rifle (has a different optic on it now):


The stock is comfortable and allows for adjusting length of pull. It has a steel striker plate for whenever someone needs buttstroking, a storage compartment for your skittles, and a battery storage tube on either side of the cheek rest. Not cheap, but not as expensive as a higher end Magpul stock.

If you like the fixed length of the A2 stock, a buddy of mine has build a 20" precision AR (and hits reliably at 800 yards with it), and he uses a VLTOR ARM buttstock, which is a little lighter than the EMOD, and has the same cheek rest and waterproof battery storage as the EMOD:



If I were building a fixed length stocked AR right now, that's the one I'd probably go for.

[bnc]

My 20" has been just fine with a Spikes T2 buffer.

[glazer1972]

I had a 20" govt profile upper with a LMT Sopmod stock for quite awhile. Worked great. I now have a 18" HBAR upper on it. I think the 20" govt profile actually balanced a little better.