Daryl

I find it hard to believe your comment " I firmly believe that the smaller the diameter of the case in a 3 1/4" long case, the harder it is to get the ctg. to shoot accurately with either smokeless or black powder. Those were my findings from using .40 through .50 calibres in Sharps ctgs. of 3 1/4" length."

As has been mentioned, 450 also has the advantages of using the more readily available 458 bullets.