After further research and testing, all the eject issues on the M41 were with one magazine (I finally numbered them, which allowed me to track failures). I have no failures out of about 200 rounds once I isolated the one magazine.
Further testing indicated the one magazine is getting an ejection failure about 80% of the time after the first round only, and only when loaded with more than 3 rounds (works fine with only 2 or 3 rounds, I did not test 4)…
This is why I always suggest numbering magazines before anything else. Lots of people go from "It happens with all my magazines" to "Well, just this one...". If you don't have your magazines numbered, don't say that it happens with every magazine, because you just don't know.
And the very first thing anyone will tell you at that point is, "Number your mags."
Various points:
(1) The "oil the top round" thing works by virtue of the oil taking up volume in the chamber, increasing the pressure slightly (liquids don't compress). It's a band-aid fix, and not a very good one.
(2) Cleaning every 200 rounds is excessive as hell. With
light periodic lubrication, you should be going 1000-1500 rounds in most environments, and very likely more than that. I've seen more problems caused by over-lubricated rimfires than dirty ones. If it's still functioning, just keep it lubed.
(3) For whatever reason, your problematic magazine is riding high in the frame. This causes the top round to rub on the bottom of the slide as it moves, slowing the slide down and retarding ejection. This is common across target .rimfires. Feeding .22LRs is pretty tricky.
(4) The same stoppage--stovepiping--can be caused by a recoil spring that's too weak relative to the strength of the ammunition, not just too strong like most people think. If the slide cycles too fast, it catches the case still in the chamber.
