What can be used to assemble pa10 gen2 lower what other uppers work
Any Gen 2 or Gen 3 PSA upper will work. There may be other manufacturers uppers that work but since there is not an AR10 standard like ar15s there is no guarantee they will. It is best to stick with the same manufacturer for ar10s.
however, we recommend matching Gen3 lowers to Gen3 uppers for best appearance and performance. This is what they say … I guess the gen2 has expired I hate to spend $$ on gen 3 upper if they say that
Gen 3 added BCG cuts into the buffer tube thread area. Otherwise 2 and 3 are cosmetically the same. The reason they have to add that caveat is because there is not a standard.