MontanaMan,

So far IMR4451 has been SLIGHTLY faster than my present batch of H4350. A good example is my 7x57 with 160-grain GameKings: Used to use 46.0 grains of H4350 for right around 2700 fps. Matched it in velocity and accuracy with 45.5 IMR4451. That half-grain has been typical in cartridges using charges of 45-60 grains of powder.

“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck