So I have a 12.5" AR pistol chambered in 277 Wolverine that I never shoot, and decided to part it out. Had some Wolvy guys interested in barrel, but not full upper, so I stripped barrel out. Now I'm wondering how hard it'd be to convert to 9mm? I saw a place with 9mm uppers on sale, w/bcg and ch today, but not sure what else needs conversion besides magwell?? Any input would be great, even if its saying "don't do it"