I’m planning on a 20" rifle build with either an A1 or A2 upper and need to know if I should use an “F” marked or regular front sight base. Thanks.
You won’t need a F marked FSB with an A1 or A2 upper receiver.
OK thanks…whats the differance anyway?
F marked FSBs are for flat top uppers. Used with a A1/A2 upper may cause your front sight post to be WAY low in the FSB for proper zero.