Winchester .22 ammo is terrible.
I hate to be the one disagreeing with everything here bit I've got to disagree at least part of the way. I've found that Winchester Super X 36gr CPHP .22LR is only okay in a semi auto, but I get by far my tightest groups in my Savage MKII with it. For me that load of Winchester .22 produces sub 1" groups every time at 100 yards on a windless day. My record is .78" with a 5-shot group. I've probably tried a dozen different rounds in that gun, including the CCI go-tos for decent accuracy. Winchester proved best in that gun.