The Pro-Mags do really well. No problems so far. Yeah, they are inexpensive compared to factory! I use them as range mags so I won't get upset when they get trashed from abuse!
Anyone else use Pro-Mags?
Sorry to hear the heartburn over the Pro-Mags.
My P-99 is a .40 and the Pro-Mags seem to be doing okay so far. In fact, I wish I would have used a Pro-Mag when I was trying the "mag-slap chamber-a-round" trick that was discussed. (See my post and aftermath pic under "Bug or Feature")
I responded regarding your situation in the other thread (it's not your fault and covered under warranty). Let's hope the Assault Weapons Ban sunsets next year so they won't have to make these things so tight you can't possibly get an 11th round in the mag, putting the entire system under unnecessary stress.