Collapsible m4 stock on rifle barrel: which buffer to run?

[Trifecta]

Evening gents,

I have been tossing around the idea on throwing a mil spec 6 position buffer tube and BCM B5 SOPMOD stock on my AR-15A4 (flat top upper, 20in bbl rifle length gas system) to replace the A2 buffer tube and stock and was curious as to which buffer would I run in it to keep it reliable?

I know this is sort of a bastardization but this rifle currently doesn't fit in my 'go bag' and is just about 2in shy of doing so and a collapsible stock would make it fit. Another reason being that with the consideration of my chest rig can be a bit of a stretch when using this rifle and a collapsible stock would alleviate that issue as well, 2 birds with one stone kind of deal.

Another option would be the Magpul MOE fixed carbine stock but I think I would prefer the adjustability factor.

Thanks!

I realize I worded the title a bit funny but I'm sure y'all understand

[MistWolf]

The MOE fixed carbine stock is designed to work with a carbine RE. It uses the raised ridge to stop it from spinning.

A rifle length gas system will work fine with a carbine RE and an H2 or H3 buffer. But your simplest solution would be to use the A5 receiver extension

[Iraqgunz]

Use the Vltor A5 with an A5H3 buffer and green Sprinco spring. If you want to use the standard lower receiver extension, get a blue Sprinco and H3 buffer.

[Wolfpack45]

Another vote for the A5 Vltor system. It is essentially the same thing as the rifle buffer system in its function but adds the ability to use adjustable stocks.

[markm]

Another vote for the A5 system. That's what it was designed to do.

[Trifecta]

Thanks for the info guys, never heard of the A5 system before and now I'm looking for a place that has one in stock.

Quick questions, does any normal m4 collapsible style stock fit on the A5 tube or would it require a certain stock to work? I would still like to utilize the BCM SOPMOD stock.

[markm]

Any milspec diameter stock fits. So you can just buy the RE, Spring, and Buffer.... Or if you need the castle nut and end plate too, buy the kit.... Or piece it all together as you can find the parts. There's several ways to skin that cat.

[MSparks909]

Thanks for the info guys, never heard of the A5 system before and now I'm looking for a place that has one in stock.

Quick questions, does any normal m4 collapsible style stock fit on the A5 tube or would it require a certain stock to work? I would still like to utilize the BCM SOPMOD stock.

Check out this video showing the differences between the 6 and 7 position A5 kits. You're going to want the (RE-10A5) 6 position stock to work with your SOPMOD stock.
http://www.youtube.com/watch?v=UnrVJT4UU10

[markm]

SOPMOD will work on either... you just may give up full collapse on one or the other. Frankly... I buy either tube that's available when I need on and don't give it a second thought.

[bshot]

http://www.midwayusa.com/find?userSearchQuery=vltor+a5+

I purchased my A5 kit a la cart since I wanted to purchase the green spring and H3 buffer.

Midway had a sale last week:
A5 RE - $40
H3 - $40