Ya got yourself a lemon. If you have purchased this new, you should be sending the pistol back to Ruger so they can figure out what to do. If ya bought it used, welll... that's probably why the thing was sold.
I've never heard of the Ruger MKs having malfunction issues to this extent. You shouldn't have to be limited to CCI Select to have a so-so day with this fine piece. Ya should be able to fire majority of ammo brands without issues.
I took the LCI out of my mklll 22/45 just because of the looks, but it wasn't
causing any feeding/ eject. issues.