Harold I shoot several damascuss gun but shoot all 2 1/2 inch shells regardless of what type of barrel steel. You can use low pressure 2 3/4 inch shells in 20 & 16 and several people do load them. I just prefer the shorter shell but its a personal preferance. For your damascuss gun order a case of RST (I would go 2 1/2 inch) and enjoy the gun and the absence of recoil. Your not a clay target shooter so a mixed case of RST's will last you a long time....even in Channing
