I'm still not following. 4451 is a "4350 class" powder which seems to me to be on the slow side for a 308.
In use I do not find it much slower than Varget and I get a little better velocity out of it over Varget. Varget MAY be a little easier to get right in a 308 case. For the better part of my time reloading 4350 was the .243 powder and I have used it for 58 grainers on up to 100s. I quit using it when I got Varget, and the only place I use it now is in my 270 with 110s. I tried it there to test the bullets a little and it handed me itty bitty groups. I though I was just going to burn up some powder running tests.
4451 I have come to really appreciate. It tends to be clean and quite linear. And, it usually gives me better velocity with equal accuracy.
