Preferred buffer setup

[Gary556]

I'm running a Rosco 11.5 k9 with their proprietary gas length, patrol. I have a silencer co velos 5.56 full size. Currently running the bcm mk2 mod1 t1 buffer system. I haven't ran into any issues while suppressed, but I'd like to play with a couple different setups to fine tune and get the most reliability possible.Unsuppressed its runs a touch over gassed but the barrel does have a larger gas port and I've read they are over gassed.

Anyone have any recommendations for maybe a springco or maybe the geissele braided spring?

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[orygun]

@titsonritz or @Cerberus Group should join in and help. They seem to be up to speed with this stuff.

 

[Cerberus Group]

I'm probably the wrong person to bring into this conversation, as I tend to look at conventional parts to cure problems vs new fangled, you gotta have parts because of wicked marketing.

But, here goes...I'd change out the barrel to get the proper gas port to begin with. You're trying to compensate for someone's lack of attention to deatail. Really, that's not your job to do.

You're close to Mark 18 length, and that setup has been perfected, so look at what works with that...a shorter gas system.

I'd go with a A5 buffer system with a Sprinco green spring and a A5H2 buffer to start.

 

[titsonritz]

The BCM MK2 Mod 1 buffer system is the equivalent of the Vltor A5 buffer system of which I am longtime proponent and stated this thread on the subject awhile back…

VLTOR A5 Buffer System Overview

I've been a proponent of the A5 system for quite a while now and I know I've swayed a few others in that direction. I can honestly say I won't build a personal carbine without one. Here is an interview with Nick Wantland, head of marketing and sales at VLTOR Definitely worth a read. Vltor A5...

www.northwestfirearms.com

Other than that, I don't have much to add to what @Cerberus Group said, he is spot on.

 

[Duneblaster]

You could even try an AR10 flatwire spring with the A5 setup. That or the green sprinco. The orange sprinco springs are about twice as heavy as normal AR15 springs. A new barrel with the right sized gas port is the best option. It will be easier on your bcg. The AR design wasn't meant to run hard n' overgassed.

 

[orygun]

What's the easiest/best way to tell if your gun is overgassed?

 

[titsonritz]

What's the easiest/best way to tell if your gun is overgassed?

Pin gage (not drill bit) the gas port prior to assembly or know the barrel you are purchasing.

 

[Cerberus Group]

Barrel Gas Port Size Parameters

10.5 – C - .070-.073
11.5 – C - .071-.073
12.5 – C .068-.071
13.7 – M - .0785
14.5 – C .0625 / M .076
16 - C - .0625 / M .076
18 - R .0995
20 – R .093



Barrel Length Port Distance
Pistol - Less than 10 inches 4 inches
Carbine - 10-18 inches 7 inches
Mid - 14 – 20 inches 9 inches
Rifle - 20 plus inches 12 inches