I was thinking about 25,000 PSI loading levels. If you figure the 18,000 PSI Trapdoor loading level is the maximum for the Contender, how do you figure the other two cartridges can top the Contender if loaded to the same pressure level? Their PSI levels are into the high 40s. This does not compute....Do you figure the Handi-Rifle is a better gun? It is factory chambered for the .444 Marlin, .44 Magnum, and .500 S&W, all at 40,000 plus PSI.
Here's a link to Mike (censored word) who says the .45-70 in the Contender can be safely loaded to the 28,000 PSI to 32,000 PSI level, or that's what I think he's saying anyway... http://www.(censored word).com/FAQ/max_pressures.htm