I don't understand why anyone would waste time and money shooting 50 shots with a .458 Lott every week, whether squib loads or real loads.
After I got sighted in, I didn't fire my .458 Winchester except to check zero or when hunting. Any skill you can get from "practicing" is directly transferrable from smaller calibers. Except for handling recoil.
I recommend lioading five hunting rounds and five without powder or primers. Put all 10 in your pocket and then shoot offhand, single loading one at a time without looking at or feeling the primer pocket. That will tell you how bad your flinch is.
The best load I found for African dangerous game was 72 grains of AA2230 wth a 450 grain bullet (TSX or North Fork), F215 primers. Velocity was 2250 fps. North Fork 450 grain flat-point solids will penetrate deeper than 500 grain round noses due to the cavitation effect. Recoil was noticeably less than 500 grain loads at 2200 fps.
The effects of recoil are not well understood. Not only might it make you flinch but also lengthens the time beween shots, due to muzzle rise.
