I gotta say that I mostly agree with this. In the current state, every wall can break only by using revolver, which is kinda silly. I would personally maybe only let the wooden wall to be destroyed by guns, but stone and metal wall should be destroyable only with some kind of explosive, also the wood is shot very quickly, I would atleast double or maybe triple the durability there. That said... I would make explosives hard to get, they could be inside the safe or atleast in the airdrop or be crafted through more steps... for example have blueprint for gunpowder, blueprint for explosive (which would already be able to destroy stone walls) and then out of them have blueprint for some kind of explosive charge for destroying metal walls.