I just bought 3 magazines for my 422 magazines and none of them will seat. I called S&W about this and was told that if I would ship the gun in they would fit the mags for me. At this point I don't want to spend the $80 to overnight the gun to Massachusetts, so I'd like to see if anyone has a fix for this.

Sand the outside a bit. Wipe down with oil. Also take grips off and try again.

I will try this but maybe I should have mentioned how they don't fit. They seem like they're hitting something on the top if them while inserting. They go in just fine with the slide open, but if I drop the slide it gets seriously locked up about a half inch out of battery.

Interesting. I just recently purchase two 41/422/622/2206 mags for my 2206 and they all work just fine. Maybe it is your mag release out of spec.

Well I could see that the slot on the mags for the catch was slightly higher on the original mag, so I filed away on the slot until I could seat the mag and the slide would go into battery. Took it out to shoot and it wouldn't fire unless I used my off hand to cram the mag in even further. I'll have to hit it just a bit more and see how that goes. I'm only doing this on one mag until I figure out the solution.

For the record, I tried sanding it down a bit and taking the grips on and off. Nothing.