[MikeG]

Only way to know what your rifle will take is to start low and work up.  I'd personally start at about 20 grains with the 335gr bullet and go from there.  Powder lots do vary somewhat.  As no expansion is really necessary, I'd just stick with whatever load ended up being the most accurate, and not worry about whether it was the top end or not.

Deer load?  The 335 will do for Bambi very nicely, however so would nearly any other bullet weight.  Thumb through several current loading manuals, most of them have sections of "Ruger - T/C only" loads for the .45 Colt and these should all be OK in your trapper.

 

[MikeG]

You need to put a scope on that gun and enter the next benchrest match you can find!  That would sure annoy anyone who has spend several thousand dollars on a benchrest rig when the guy next to him is shooting a lever gun!

Great results.  This would also be suitable for varmit hunting, if you could line up 30 or 40 prarie dogs in a row it would be very economical per shot also.