445 Supermag loads

[300winman]

I was just reading some past posts on the contender carbine and saw that the contender frame can not handle higher pressure rounds in the big bore calibers. Specifically they were talking about the 45-70 only being able to accept trapdoor level rounds.  I just bought a 24" 445 supermag barrel for my contender and was wondering what levels I can reload to.  I know these are 2 different cartridges, but the operating pressures on the contender frame is more the question I have. The trapdoor levels are below 28,000 cup and the 445 can be in the 35,000+ range.  Just looking to load a safe round for my contender. Can it fire the same rounds I put through my Dan Wesson?  or do I need to back them down a touch?  Any input appreciated. Thanks!

[Lone Star]

The .445 SM can be loaded to the same pressure levels as the .44 Magnum in the T/C.  The reason that the .45-70 is loaded to lower pressures is the larger inside diameter of the case.  Pressure does no work unless there is an area for it to push against, so the larger the cross-sectional area of the inside of the case, the more push it applies to the breech.


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[swampthing]

According to the yellow, 2000 Edition, Complete Reloading Manual For The T/C Contender... and assuming this is for hunting. Using Federal 210 Large Rifle Primers, and, Hodgdon H4227 starting load for a 300g Sierra JSP is 24.5 grains. With Winchester W296, and the same bullet, 27.4g to start. They say that this particular chambering does not lend it self to reduced loads and not to go bellow the listed charges. If you find that this is way more than necessary IMR Trailboss powder is great for the large capacity cases, my .444m does excellent with it.