Lots of food for thought here thanks guys - my intention was to use the heavy bullets, probably Woodleigh Protected Point spitzers in 300 or 350gr depending on the most accurate. The rifle will be slotted in between a .338 Win Mag and the .458 Lott so heavy bullets are called for to give a real improvement over the .338. The conversion would certainly give a real increase I like the idea of being able to download the Wby to H&H levels if wanted as I will most likely be using the rifle for Big Game competition as well as hunting.