Walmart on 27th should have the Mini Mags, if not I have been substituting the Winchester Super Speed HP (red box next to CCI Mini Mags) =1330fps with 37 grain bullets ) with good results and sometimes a few cents cheaper.
Also you might try the CCI AR 22 tactical- was loved by my Chippea 1911-22, (1200 fps-40gr with a different bullet shape for more reliable feeding) or the Federal (ugg) Auto Match (1200fps/40gr) (which my old Marlin 60s just adore)
you might stay away from the Winchester XPERT HV (unfortunately a company I usually prefer) bulk. Last time out with the rifles, the lead seems to be a shade larger than the brass, or maybe just soft, but occasionally the lead would push back over the brass and lodge in the chamber. ( A bad batch, maybe I hope).
If you Really need some Mini-Mags, I could sell ya a box (I have some stockpiled in both Hollow Point and Round Nose)
Side note- the Mini Mags seem to be the preferred ammo for the Walther P22 also. Only thing my mom will run in hers.