I had purchased this powder thinking it might be ideal with 80 grain bullets in the 22/250. Previously, I had used 4831sc which worked well enough as far as velocity was concerned but which didn't really give methe accuracy I wanted.
Anyway, I finally got around to trying the 4451 and it works great!. 38 grains behind a Sierra 80 gives me 3260 with very mild pressures and the accuracy is more than adequate (five shot groups under 1" at 300M). I feel there is at least another 100 fps available with a little more powder but 3260 is satisfactory for my purposes and accuracy and consistency were my main goal.
This same powder also enabled me to easily exceed 2800fps with 168's in my 30/40 target rifle and again, accuracy is excellent as is consistency.
I like this powder. GD