Years ago I seen an article in either the Guns Digest Shooters Bible on a Big Bore 94 converted to the .458 2" American. That round is very similar to the .450 Marlin so you can expect similar results.

It's been awhile, but I remember it as being an indepth article with loading data, performance and so on.

Has anybody else seen this article? I think it came out in the 80s.