If I purchase a Rock River Arms upper, can the muzzle be a threaded one? A threaded muzzle will be legal since the upper will be on a FAB-10 lower. Will there be any additional costs?
Can the uppers come with chrome-lined barrels or is that option only for complete rifles?
Can the upper be purchased with green handgaurds in place of black handgaurds?
Also, do you have green Fobus G27 grips?