3900 series ProMag Issues

[txice]

I have always heard that the ProMags have had issues reliably feeding the 3900 series pistols. I have one coming in and it comes with a few of these mags. Does anyone know if replacing the springs with new OEM mag springs would help? Is it something with the geometry of the mags perhaps? Follower issues? Locating more OEM complete mags for these guns is tough and wondering if I can assist these ProMags in being more reliable.

 

[WR Moore]

Mythbusters proved that you actually can polish an example of fecal matter. But, you have to start with the right fecal matter. If Mec-Gar makes a mag for any of the 39 series listed below, you'd be better off going that route.

OEM mags for the 439, 639 and 3906 should work just fine.

 

[stansdds]

Unfortunately, Mec-Gar has refused to make magazines for any of the S&W single stack 9mm pistols. I have read a few posts about replacing the ProMag spring and follower with S&W spring and follower and turning the ProMag into a reliable magazine. There is also the possibility that this particular magazine will be reliable. Several people have found the ProMag single stack magazines to function well. I'd say test it before rebuilding it.

 

[PeteC]

I have one aftermarket (not factory) magazine for my 3913 which came with when I bought it in the classifieds.

The follower may not have that much effect on feeding until the last round is stripped from the mag. Until them it is mostly the position and angle of the lips of the mag relative to the feed ramp, the shape of the bullet ogive etc.

I've had no issues feeding or otherwise, but the follower does look very different. Upper right in pics 2 and 3 below.