I just fired 100 rounds of the Magtech std velocity in my K22.
My very subjective observation, only for this revolver that I shoot every week, is:
1) Ammo seems as accurate as CCI standard velocity and more accurate than the bulk stuff by Federal, Winchester, CCI Blazers and Remington Golden bullets.
2) Ammo is dirtier than most brands I use (except CCI Blazer);it has a waxy coating which the Blazers don't seem to have.
3) Misfires are much more common than the brands listed above. I had 15 misfires out of 100 rounds; 8 fired the second time around, five required removal and rotating before rechambering, two rounds wouldn't fire no matter what I tried.
It may work fine in some of my other rimfires; I probably would put this toward the bottom of the list for this particular K22. I haven't been particular about the rimfire ammo I shoot the last couple of years; I shoot what I can find for sale, when I can find it.