consistency and anyone with a brain looks in the chamber before they drop the hammer on any weapon, proven science is that doing the same thing all the time keeps you from screwing up. If you store your guns with the safety on, no round in the chamber, then always do the same, if you store your guns with the hammer down safety off then always do the same. If you pick up a rifle with the safety on or off, check the chamber before handling it any further, a lot of dumbasses have AD's because they keep the safety on, pull the trigger to drop the hammer and don't remember if the gun had a round in the chamber or not. springs are cheap, and check the chamber.....
