The nose portion of the bullet works best when it's fat enough to be engraved with the tops of the lands. I have an early Lyman 314299 which was originally developed for the 303 British cartridge. However I shoot this bullet in a Finnish Moisin M27 whose bore slugs out at .3115 and the bullet is sized at .3135. But the nose is engraved by the lands. Probably about .002 but does stabilize that long bullet and I get 2 to 2.5" groups at 100 yds. And yes that is when my 74 year old eyes cooperate. Frank