It depends on your breech plug. The oldest models have a straight slot head. For that I use a CVA Staghorn Magnum breech plug wrench. For the modern hex head ones, I use a Black Diamond Deluxe Breech Plug wrench. I might have another Black Diamond wrench around, but I would have to look. I once had quite a few of them. If that is the one you need I might be able to help you out.