On the Pieper I mentioned the barrels opened until the bottom of the forearm knuckle hit the bottom of the frame. This obviously puts forward pressure on the forearm lug. On hammerless guns the cocking mechanism often serves as the check though some have a separate check as well. Some of these may not be as accurately fitted as desired. Bottom line is on any break open gun "Gently" fully open the gun. Make certain there is clearance between the forearm knuckle & the bottom of the frame. If there is not then it needs adjusting if possible. If there is nothing to adjust as on my Pieper it has to be handled very carefully. Do not open it hard but as gently as possible when loading. Never Ever carry it around open with the weight of the barrel putting forward pressure on the forearm lug. This can even be in your gun-room at home, does not ave to be out in the field, of course the rougher the terrain the more pressure is apt to be applied.
