Mk12 SPR Buffer help needed New to thread

[Alaska3006]

@Hseureau

I’m new, my first AR15 build. Here are the specs to my upper
Krieger barrels 18 inch stainless steel 1-7.7 twist .750 diameter with a rifle length gas system
Seekins Billet upper
Spikes tactical full auto NB BCG
Surefire 5.56 muzzle brake
PRI Gen III hand guard
Syrac ordinance .750 adjustable gas block

I’m almost done with the lower but I cant decide on what kind of buffer system to use
Some say Rifle buffer
Some say Carbine buffer

Rifle will shoot smother?
Carbine won’t?

Please advise me on which to use or the reasons for choosing either if possible!

As you can see THIS IS NOT A TO SPEC MK12 I just want the most accuracy out of it I can get and as it appears, the buffer is the only thing up in the air.
Money is not an option or wait time, the barrel took almost 8 months haha. Also, what is the best of the best for either, I don’t want to slack on any part of this build

Heres a pic with my colt le6920 lower

I have the Rifle Super 42 Braided Buffer Spring with the Kynshot Rifle Buffer
Excellent in my MK 12 Mod 0

[Hammer_Man]

Vltor A5 system works great on three SPR rifles I’ve built.

[ViniVidivici]

If it’s gassed and built right, it’ll run fine with any of the regular options.

A5 or H2, in that order, will be smoother and less jumpy.

Very happy with H2 and standard carbine spring in my 18"er. I think the adjustable LOP and lighter weight of a carbine stock is a huge advantage.

I may be wrong, but I think the original accuracy standard for the original MK12 was 1.25 MOA.

[AndyLate]

@Clint

For max performance, the A5 or rifle buffer is what you want.

The choice between the two is user preference and ergonomics.

What does performance mean in this context? (Not being a sa)

I really have become spoiled by adjustable AR stocks, especially with higher power optics. The ability to move the stock in or out a click to account for clothing or shooting position trumps the things I love about a fixed stock.

IMHO, A5 is the clear choice. Rifle action spring, a broad range of buffer weights, numerous stock options.

Andy

P.S. Thats a heck of a nice first build!

[BobinNC]

@Hammer_Man

Vltor A5 system works great on three SPR rifles I’ve built.

Ditto

[tehpwnag3]

With an adjustable gas block, you can run a standard carbine buffer and spring with no problem. Just be sure to tune with your desired ammo.

[Uncas47]

@Renegade04

The Mk12 SPRs have been seen running a variety of stocks. Before I built my Mk12 Mod 0, I did a lot of research as to what stocks were used. Since the Mk12 uppers were originally mounted onto M16A1 lower assemblies, I started out with an A1 stock, but later changed to the SOPMOD. I prefer the adjustability and the comfort of the SOPMOD compared to the A1. Additionally, you will see variations in the grips as well. Where Naval Special Warfare units comes into play, they have the options and ability to outfit their weapons as they need to. This is why you see different variations in their weapons.

I use essentially this setup on my A4, LMT SOPMOD, 6 pos MK 18 RE, carbine spring, and have used H2 and H6 buffers and notice no difference with IMI 193 or 855. Very smooth and 100% reliable. Adjustable over fixed anytime.

Edit to add, this setup sees mostly prone shooting where the shorter LOP allows me to square up behind the rifle better.

[vicious_cb]

Guys, Im pretty sure he’s figured it out after 6 years.

[Disciple]

@vicious_cb

Guys, Im pretty sure he’s figured it out after 6 years.

Forum suggestion: change the background color of posts after a period of time so people who don’t read the date stamp have another indicator of age.

[Uncas47]

@Disciple

Forum suggestion: change the background color of posts after a period of time so people who don’t read the date stamp have another indicator of age.

Excellent idea.

[ViniVidivici]

@vicious_cb

Guys, Im pretty sure he’s figured it out after 6 years.

Oh, **** me I didnt even realize this was a damn necropost…good thing it wasn’t a rattlesnake…

[Uncas47]

@ViniVidivici

Oh, **** me I didnt even realize this was a damn necropost…good thing it wasn’t a rattlesnake…

Hahaha, at least the last few of us were still respirating.

[tehpwnag3]

Oh good grief.