Many years ago, I bought a New England Arms break open 12 gauge shotgun. I bought a survival stock and several adapters that fit in the stock. The calibers I bought were, 22, 9mm, 45 and 7.62x39. One gun, many calibers. I tried them all, liked them all. It doesn't turn you shotgun into a sniper rifle, but one that uses different shotgun, handgun and rifle calibers.