I recently purchased a new .22 pump rifle. I zeroed it at 25 yards with all three of the above rimfire ammunition types. Why, after zeroing with .22LR then checking the point of impact at the same range with .22 short and .22 long ammo, did these lower velocity rounds impact higher on the target than the .22LR? In fact, the .22 long POI was about two inches above the .22LR, and the .22 short impacted about two inches above the .22 long. I would have thought that at a close range like that there would be little difference in POI and, if anything, the slower moving short and long rounds would strike just a little lower than the faster .22LR rounds, all other things being equal of course.