I bought my 41 in the mid nineties and with CCI standard velocity the failure rate is a few percent. Not nearly as bad as what you are describing but still annoying. It runs great with CCI Minimags. I have heard that 41s are designed for standard velocity and might get beat up with high velocity ammo but after trying a few fixes I gave up and just use Minimags. I would rather chance increased wear than live with an unreliable gun. I did buy a buffer.

The majority of my failures were the type where the slide went far enough back to eject the empty but not far enough to pick up the next round. So I ended up dry firing the gun at least once every couple of magazines. I also had the occasional stovepipe.

From what you are describing I do not think you are the problem.