With the 30-40 based cartridge, the only time you would be giving something up would be with the heavier bullets at max pressure, but with the lighter bullets, it oughta do fine. And the .405 can handle some big critters.
Once you get to that size bullet at a good sectional density, moderate velocities will do quite well.
I think I'm going to keep my eyes out for a good used .444 donor action, and build one in .405. I honestly think it would be easy to do, and tons of fun to shoot.
gary
