Buffer compatibility

[IW378]

Asking this question for a buddy of mine who is getting ready to build his first AR. He's dead set on a 20 inch rifle but he wants a collapsible buttstock.
Will a carbine style buttstock and buffer assembly work with the rifle length
gas system. All of mine are featureless carbines and I use a1 or a2 rifle stocks
and they work fine with the carbine length gas system. Just not sure about the other way around..

[G-forceJunkie]

What upper you put on it has no bearing. Rifle reciever extension=rifle spring and buffer. CAR buffer tube=Car spring and Car buffer.

[Sky_DiveR]

I don't think there would be any issues. I have a shorty stock (carbine length) on my 20" and it works fine. I use Tubbs CS flatwire buffer springs so that may be an issue if you use a stock buffer spring but I don't think so. I'd say go ahead and do it.

[joelogic]

Buffer relates to the stock not the upper.