I don't think that the rule of 96 is very useful for most guns above 12 or below 16 gauge. The rule of 96 would give a gun weight of 7.5 lbs for a 10 gauge with the old standard load of 1 1/4 oz of shot, but I don't think many 10's were built that light. That is a reasonable weight for a 12 ga hunting gun with 1 1/4 oz, 3 1/4 dram loads, but the 10 used 4 drams or more, and that has an effect.