I just bought a model 59 myself...I tried a Mec-Gar mag while I was in the store, and it wouldn't lock into place, and the slide would not lock back with it. They had a Pro-Mag that fit and worked...it looked exactly the same as the Mec-Gar (and I tried two different Meg-Gar mags there.) I only bought one, since if I recall correctly, I've read some mixed reviews on the Pro-Mags (for other models; I don't know much about the model 59 yet.)
As was earlier posted, blued magazines were supplied by S&W with nickel 39s and 59s. Any nickel magazines you may find for either is aftermarket. I recommend use of the S&W magazines, as they usually are best in terms of reliability in those guns.
As was earlier posted, blued magazines were supplied by S&W with nickel 39s and 59s. Any nickel magazines you may find for either is aftermarket. I recommend use of the S&W magazines, as they usually are best in terms of reliability in those guns.