Building 2 AR 15s

[jmichelin84]

Hello all, im looking to get some advice on a couple builds I'm working on.
I want to build some A2 style ar15s, A2 front sight gas block, magpul rifle furniture, my question is, should I got 18 or 20 inch barrels?

[JSantoro]

This is not a Custom Build topic; read the stickied threads there.

Moved.