quite often that is associated with hammer notches that were cut in the wrong position, The hammers cock before the gun is completely opened. As you try to get the barrels open farther you are fighting the hammer springs. I know it sucks but most of the time to fix you have to weld up the hammer notches and recut a little further " so that when the barrels are dropped or broken open, they clear the reciever and the sears engage and hold the hammer srpings at bay.
Otherwise when you go playing with other parts you get into the law of unintended consequences with one part affecting another in a way you dont want.
Thats my 2 cents. hope it helps.
