Well, if you want to discuss the basics let it be so unless you are testing members of the forum ! Given the same charge, ranges achieved by 45 caliber gun will be less than 52 caliber - 6975 mm length Vs 8060 mm length. The shell inside 8060 mm barrel will get greater acceleration as also spin. It is 38 km Vs 45 km. Seven km is a considerable range difference.