Hello hunta223rem,

I was already in this situation and my Brno .458 Win. Mag became a .450 Rigby Rimless.

Reason for this: in the Win Mag configuration the rifle had feeding stoppages.

The rifle was rechambered without problems and proofed at the german proof house in Ulm.
Afterwards the cartridge feeding and the ejection port had to be modified and function improved.

I still think the long magazine of the Brno makes the 450 Rigby a very useful chambering in this rifle.
However, I feel that the Lott configuration would need less gunsmithing for feeding and has at least one cartridge more in the magazine.

best regards
Rolf

PS: I am astonished because of your nick (223 rem) in the NitroExpress-Forum... :-)