After trying my 18 rd. ProMags I have decided they are junk and more trouble than they are worth . Tried loading different ways but still all I get is Failure to Feed over and over again . The bullet catches on the top of the chamber and mostly bends the rd. or puts major dents in the case .
I bought two of these 18 rd mags. I have only had trouble such as FTF with some ammo (like Winchester). Interestingly enough, I recently bought a Tippmann semi auto and it too hates the Winchester. At a recent trip to Wally's they had Federal Bulk 550 rd boxes. First experience with it for me. Both the Glock 44 and the Tippmann were 100% smooth (no issues) with this ammo. I fired 200 rds of it. In retrospect I wish I had purchased all 8 boxes they had at the store.
I haven't tested the ProMags as extensively yet (compared to the standard Glock mags). I have fired about 300 rds so far with them. Also, for comfort, I only load them with 15 rds which might help.
I recommend the following ammo:
Any CCI (including bulk lead nose blazer)
Aguilla
Federal Bulk copper plated 36 grain hollow point
Avoid at all cost:
Winchester (Highvelocity, X, etc.) I would only use this in a revolver or bolt action
Herters (which I think is repackaged Winchester)