I have a couple and they won't put my Springfield RO into slide lock. No problems with Tripp or Wilson mags though. No problems with the cheap Brownell 10 round mags that I use for practice either.
I have a couple but had to touch up the follower with a file , would stick/bind sometimes ,
other than that , have been working great in my norinco np29
Bought them from a ex site sponser about 2 years ago
I'm looking to use them in an NP29 also. Going to buy them from the ex site sponsor that we do not speak of.
How old are your mags? I've heard that Mec-Gar has updated their design.

What site sponsor has them in the West



























