I use IMR 4064 behind 55 gr. Midway Dogtown (a repackaged Nosler Varmageddon, the FBHP version), with excellent results. Avg .6 @ 200yds with groups as tight as .3 @ 200yds.
Same gun as you (12FV 22-250)
Not your bullet and definitely not a match bullet but might be worth a try.
Also have had great results with Varget but when I found 8 lbs of 4064 at a good price I got it.

Darrell