bushmaster 16

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    Gunsmithing Bushmaster 16" Upper: Bolt & round issues

    Hey guys, I know I'm new here... a buddy of mine suggested I throw out this problem here: I'll try to be as verbose as possible. I'm new to most of this and trying to learn quickly. Here is my problem: I just bought a brand new Bushmaster 16" upper. The lower is a Sabre Defense receiver with...