I did the same thing as you with my 22-250. However the culprit is the distance you are sighted in for. If sighted in for 300 or even 200, your groups will not spread over 4" from slowest bullet to fastest bullet. Spend some time with a ballistic program and you will see what I mean. Sight in at the closest distance possible, say 50 yds. Then your groups should spread close to 8" at 325. The first ladder test I did, at 400 yds, gave me a sub MOA group over a 10 shot spread from lightest to heaviest load. Thinking I wasn't far enough away I repeated at 650 yds with the same result, but I was adjusting the scope to those distances.