I tried just about everything, including being sure that there was no "wet" lube at all, going to a dry lube. I spoke to a number of people who had seen the problem, and all agreed that there was no "good" reason for this sort of nonsense, but shooting about 100 rounds always took care of the problem.
I know that this will sound terrible, but I wound up giving that Ruger a thourough cleaning about twice a year (of course, I would give it a wipe down, and check for lube and wear on critical contact points ever time I'd shoot).
That just seems to be the way this gun is "happiest."
Mark
You never did say exactly what you're shooting but I have a Mark I that had feed problems and after having a gunsmith strip and clean it and still having the same problems I replaced the magazine which cured it. Seems the spring was weak.
I know a few shooters who don't clean the action or bore of rimfire pistols until they show signs of malfunction. .22 ammo is so easy on barrels, etc... that cleaning puts more wear on the firearm than extended shooting. With the non-corrosive ammo available in the last 40-50 years, there's no real worry about rust. I clean my Smith 41 about every 2000-3000 rounds (internally, not just a external wipedown). Revolvers need a swab out a bit more often, because the ammo won't chamber fully at times and misfires, this is more a problem on my 70's guns than a new 617.
I guess quirks are one of those things that make guns interesting. (although I have a bit lower tolerance for this on defensive firearms) :)