Out of my 20" Rossi 92 carbine, I can get up to 1900 fps from a 165 grain gas checked, cast Keith style SWC. I use Li'l Gun for rifles. I load 'em up to about 1850, 16.8 grains, and well within pressure limits. The .357 case holds a LOT of slow burning rifle appropriate powder. I don't think I can say that for 10mm. I would THINK, without proof, that .357 would out perform 10mm from a rifle length barrel with the right loads. .357 components are also easier to find and cheaper, usually. I can see no reason to own a 10mm single shot rifle vs a .357 magnum, but I guess that's just me, eh?