“Lower” and “upper” receivers don’t apply to all guns, just certain types that were designed that way, e.g. the AR-15. I’d estimate more guns don’t have separat

“Lower” and “upper” receivers don’t apply to all guns, just certain types that were designed that way, e.g. the AR-15. I’d estimate more guns don’t have separate/distinct receivers (if the term even applies to them in the first place)