I think the Remington-UMC .303 is best because it was loaded to Mk.7z spec with a flat base 174 grain projectile. The PPU is loaded to Mk.8z spec with a boat tail. The unfortunate part is the Remington ammo which is available at distributors now is around $21 a box, dealer cost. I think the imported S&B and PPU can be had for a tad more than half that price making the Remington too expensive for new ball ammo in the eyes of many.