Originally Posted by Take_a_knee
Originally Posted by TysonT
Gas system has no effect on Buffer Spring, Buffer weight/Style, and stock selection.


If that is the case (it isn't) then those guys at JP rifles are idiots and/or shysters, and I really don't think so.

EVERYTHING about an AR's gas/operating system affects everything else.

I just put an upper together, 18in mid-length. Runs great on green tip. Bolt won't lock to the rear on ANY milder load, with a rifle or carbine lower. Change to a lighter buffer in a rifle lower and it'll run anything, even some really mild reloads.


No, I'm saying that "in theory" if you have a complete upper, you can successfully mate it to a complete lower despite the length of barrel, gas system, or butt stock. And should be okay as long as you are running the correct spring, buffer, and buffer tube configuration for that particular butt stock (carbine or standard). Except in the case of carbines where a different weighted buffers may be necessary to get proper cycling in usually "non-standard" calibers or bullet weights that are either extremely heavy or light. That being said, there are always the odd ball case where something else may be effecting the complete operation of the entire weapon (your case for example... maybe) and the components won't work, but you might not know until you try it out either.

But in the OP's question he was asking specifically about the A2 butt stock configuration.

If I understand what you wrote, you have to run a lighter carbine buffer in a rifle lower (with rifle style spring, not carbine spring) to get it to fire all loads? Are you sure you don't have another issue with your upper, like the gas port in the barrel is too small or something in the gas system is not lined up correctly?

Last edited by TysonT; 02/19/12.

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