MK12'ish build Buffer selection

[mullannix930]

I have mostly finished a build of a MK12 inspired rifle. Here are the specs on what I have:
DPMS Lower with DPMS Pardus 6position stock and DPMS parts kit and standard carbine buffer
DSA Upper (fits rock solid with the DPMS lower)
DPMS MK12 Barrel (18" with rifle length gas system) with the gas block that came with it
UTG free float quad rail
Vortex Diamondback 4-12x40 with dead hold BDC reticle

I know that some will talk crap and tell me to get rid of the DPMS stuff, but this was a fun build and the parts came from friends who I assembled some AR's for. I plan for this to be a range and coyote rifle, but would like to get the most out of it. I will replace parts for better as time goes on.

I haven't shot it yet (cold weather sucks) but am wondering about something. I am not sure if I should go with a heavier buffer for this stock and barrel setup. Also, when I go and get to shoot it, what should I look for to determine if the buffer is the correct weight?

 

[HOGTOOTH5R]

You don't need anything special bro. Just the run of the mill Carbine Buffer will do, if you run the A2 stock with the Fixed Buffer tube then you'll need the Rifle Buffer (Longer Version). The Heavy Buffers are design to fix over pressure gas problems that happens sometimes on Carbine Length Gas Systems. The original AR15s were designed to be 20" inch Barrel Rifle Length Gas Systems and they run most reliablity that way. For anything shorter like 16 or 14.5 inch Barrels I like to run Mid Length Gas systems instead.

I will Never go back to Carbine Length Gas systems again unless I'm building a SBR or a AR Pistol in which case I will definitely get the Heavier Buffers and Springs. You're Good To Go Bud.

Cheers.

HOG.

 

[ORD]

You won't know until you shoot it whether you'll need a heavier buffer or not. Generally speaking, most DPMS factory tubes tend to be overgassed from the get-go, so that's going to push you toward a heavier buffer in and of itself. You can measure the gas port diameter if you really want to disassemble it, but that may or may not tell you anything more than shooting it will. Generally speaking, I prefer a heavier buffer with a RLGS, 18" barrel and a carbine receiver extension/buffer/spring setup. I'd likely opt for at least an H2 (or an ST-T2) were it mine, but then again...it just all depends on how your rifle shoots. It'll vary somewhat depending on the conditions you are shooting in, as well as the ammo you are running in it (heavier weight bullets and/or 5.56 pressure surplus ammo...you may want/need a heavier buffer, whereas a lighter weight .223/commercial stuff may not).

Best advice...shoot it and see how it feels/functions. If you experience any functioning issues, or if your rifle seems to be really violently cycling/beating the hell out of brass, ejecting into the next county, etc., etc., then you can always address the issue then, but no need to go off sourcing "upgrade" parts/accessories just yet since you've not even put round one through the setup to figure out what's going on.