Gunner500 had a .416 Rigby bored to 505 Gibbs.
Not sure about .458 bore to 505 bore. May not be enough difference.
Call to find out.
DF
Going by memory, the 500 a-square, 460 wby and 416 rigby all have the same bolt face. The 500 for sure as it was based on the wby case. The 505 is has a slightly larger rim. You can see the difference in the cz550 comparing the 416 to 505. I dont actually have both in a 550. I know they are close. The 500 would be about as easy as it gets and would put all that powder capacity to better use. On the other hand 505 is simply cool. Kinda the polar opposite of the 460 wby. Ugg! The 'look' of the wby rifles is more constant with the more modern 500 round. Ugg again! That aside, I have a personal soft spot for the 505. That would be a great conversion. Probably doable. I guess enough effort anything is possible. Maybe a staggered magazine for 3 down in a 505.
I get it, my bad. DF was refering to the bore diameters working. Ya, that should be fine.
The two 458 would not or should not result in shoulder surgery. The 460 and 50's might cross over an invisible line. I say 'might'. The 505 with 600 grain is a hand full, I do know that. The Lott is not. YMMV. Probably does. I dont have any muzzle brakes. That probably ups the ante significantly.
