Why did IMR 4064 impact considerably lower than Hodgdon Varget at 200 meters with everything else being the same including velocity. The Lyman 50th Edition relative burn rate put 4064 one step above Varget.

I got IMR 4064 because a local store managed to get some and now I can continue to do some reloads with it.

Book velocity or your actual measured velocity over the same chrony?

Book velocity is just a guesstimate with someone elses rifle/test stand.

Your equipment, barrel resonance. The "kick" is different between the 2 powders
so the barrel "whip" is downward with the one or maybe upward with the other....

If your worried I wouldn't be. If your just wondering that's the best I got...

Just curious. I measured the velocity.

All things being equal, it's barrel resonance.