Absolutely, you can always shoot a shorter shotshell ctg. in a longer chamber when dealing with shotguns. Some of the older guns are difficult to measure, as they merely tapered the chamber into the forcing cone, rathe rthan having a 'proper' chamber. The transition from paper to brass also make chamber sizing difficult to measure. The 'case' must be kept short enough so that the folded crimp section(paper or plastic), when opened, doesn't make the ball fit too tightly in the chamber. - ie: the case must not protrude into the tapered cone section of the barrel, ahead of the chamber itself.