Besides an occasional dud round I can pretty much count on one malfunction in about every 200 rounds for both of the Ruger autos I mentioned in the above post. A stove pipe, F to eject, F to feed, etc.
Some ammo simply chokes the MK II like CCI Stingers, which are not recommended...the longer case is the reason. I haven't even tried it in the MK III.
One thing is that if you can find an accurate, reliable load for your pistol that is always in production like Mini Mags or FederaL AE, etc. then you have found the "Holy Grail" of rimfire shooting...an example is my MK II shot like a first class target pistol with the load CCI Mini Mag Plus V. It had a plated bullet ,somewhat like a wadcutter shape, but they quit making them rather quickly. The same can be said for a load called Mini Mag Sillouette which I haven't seen for a while.