What RO's can you really expect to keep up with a list of approved guns and check every gun that comes across chrono against said list? Like others have said. If it fits the box, makes weight, doesn't have a dot/comp then let it run.
At A6 there was one bay where the RO calling order would state out loud the competitors division to the other RO's....and thats the first time I have seen that. Perhaps they do that at nationals but I wouldn't know.
If the gun makes weight and is within legal dimensions, wtf difference does it matter what hammer is in it? Im pretty sure no one is winning based on the hammer in their gun.