I don't have a ton of experience with shooting a 22-250 at big-game but have shot several deer, pronghorn, and hogs with one.
The one thing I did notice is that the 60 grain partitions didn't shoot well, undoubtedly due to barrel twist. Best I could get the partitions to shoot at 100 yards was about 1.5 inches...with 55 grain ballistic tips, probably .3 or so.
But, it was good enough to shoot 130-140 yards when I tried them on my friends place in Texas. One morning I shot 3 fallow deer and 2 hogs with a 22-250 and those 60 grain partitions, all behind the shoulder, all one shot kills, all bullets passed through broadside. Exits were quarter to 50 cent piece sized. Seemed to work as well as any other rifle. Flattened the hogs, all 3 deer ran maybe 40-50 yards and blood trails were solid.
The mule deer and pronghorn I shot were a bit different, still worked fine, but I wasn't shooting the best bullets for the job...55 grain BT's.
I think a quick twist 1-8 and nosler partitions would be pretty effective on deer and pronghorn. I have other rifles to shoot deer and pronghorn with and couldn't get the accuracy I expected with my current set up and the 60 grain partition, so dropped the 22-250 off the big game line-up.