Tinker
Well done, nice looking and nice shooting rifle.
I have killed a lot of deer and pigs over the years with the Hornady 350 grain bullet at velocities from @ 1800 to 2330 fps with excellent results.
I would not hesitate to use your load for elk or black bear, and I know of a couple of grizzlys that were killed with that bullet at less velocity out of a 45/70 marlin.

When I shoot factory new brass in my 450 No2 the shoulder is pushed quite a bit foward as well. The neck length on my fired cases is about .530.

81 grains of IMR 3031 regulates with the 480, and 500 grain softs. Velocity 2080fps.
With the 350 grain Hornadays and 81 grains of IMR 3031 velocity is 2330fps.

I now use RL 15 with the heavy bullets.
Hope this helps.