I an new to these big bore guns and am buying a Ruger M77 .458Lott. The seller is givinging me 2 boxes of Win Mag's and 1 box of Lott's I am assuming that I can shoot either cartridge out of this gun? Sorry if this is a elemenary question to most (there will be more I am sure), but i must ask if i am to learn Thanks

Rakman, it's like shooting .38 specials in a .357 magnum. So yes, you can shoot win mag ammo in your Lott.

Extensive firing of 458 win mag ammo can cause erosion in the throat and subsequent difficulty in extracting 458 Lott ammunition. Definately thoroughly clean the chamber after firing win mag ammo and before shooting Lott ammo.

Two boxes of win mag ammo shouldn't cause problems, but definately clean it before putting the lott stuff down range.