I still have about 8 pounds of IMR4350, but am trying H4350 and IMR4451 in rifles. It seems that accuracy is very similar. I forget which is the most dense, but if I’m loading 100% fill, the weight is different between the three.
My 257 liked IMR4350 behind 85 grain Combined Technology bullets.
But with the same accuracy and higher velocity RE15 Is looking pretty good.

I prefer classic.
Semper Fi
I used to run with the hare. Now I'm envious of the tortoise and I do my own stunts but rarely intentionally