I have the idea that a .454 casull autoloading rifle or carbine would be an ideal deer of bear gun , the only question is what would be a good action to build one out of. Ideally a military action would be most cost effective. But, which action?
Mike

The problem you will run into is the rim. Ruger seems to have solved that problem with their 44 mag auto loader, but as I remember the original had some feeding issues. Also the 454 can run a pressures approaching 60,000 cup, if I am not mistaken. You would probably have to use a rifle similar to the M1 Garand or M1A. Those are both for cartridges quite a bit longer than the 454, so you might run into more feeding issues, not to mention weight of the rifle.
If you want a fast handling 454 I would look at the Puma(?) or Rossi(?) copy of the M92 Winchester lever action. Just my opinion.

MikeN,

just get a 45Win Mag in a Wildey with a 16" barrel and a skeleton buttstock.

Rich