I worked up some loads last year for a friend with 55 grn Hornady V-Max bullets and Varget. They shot great and seemed to be very temperature stable from summer shooting and then again last winter coyote hunting. I will look at my notes this weekend for exact load. Do you have a loading manual?
I have used Varget with the Hornady 40 grain V-Max and Benchmark with the Hornady 50 grain V-Max in Remington cases with Federal Large Rifle Match primers . My Remington Stainless Heavy Barrel shoots the 40 grain bullets well under 1/2" at 100 yards . The 50 grain bullets average just slightly over 1/2" at 100 yards . Groundhogs are very dead very quickly . Chris
My buddies old Rem 22-250 was always just "OK" with 55 gr ammo and one day 20 yrs ago we picked up a box of Federal 40 gr HP's and the gun was 1/2 MOA. Since then he has shot nothing but 40 gr bullets mostly 40 gr Nosler BT's. I think that the twist is just a little slow for what normally is a standard weight in a 22 centerfire. When I loaded for him, I think I used exactly what motox369 loaded....40 gr H380 and I think we were getting 3900 fps. If he was using a 50 gr bullet, I probably had more room to spare and could have broken 4000 fps. I guess the woodchucks never new the difference.