My 700ML shoots terrible with balls. Twist is too fast, I believe. It does very well with maxiballs, Lee modern mine' bullets, and REAL bullets all sized to .501. However, it is at its best so far with the Lee C-501-440-FN bullet designed for the 500 S&W. These are sized down to .494, paper patched with 9# onionskin to .501, and loaded by throwing the powder charge, seating a card wad, wiping the bore to the card, then loading the bullet. The charge so far is 100gr. FFg KIK powder, and groups are around MOA with the issue barrel sights. I can't see any better than that so no telling what the ultimate accuracy is at this point.