It's supposed to be regulated for a 230 grain bullet with 80 grains of blackpowder. I'm shooting it today with different loads to see what regulates. On mine the safties go on with the hammers at rest. Keeping them at rest. My guess is to stop the hammers being pulled partially back by brush or whatever and let go. I just sold a McNaughton 450 3 1/4" that the safeties worked at half cock.