Glock 17 malfunction???

Ok, lets start off with I am not stupid. I know that anything mechanical can malfunction, even Glocks and AKs. But in this case I am having trouble figuring out just what happened and why. I was at the range shooting my Glock 17. As far as magazines go I have OEM mags, Promags, KCIs, and RW&B 33 rounders. I was not shooting the 33 rounders this day, and I seldom do. anyway, I was shooting Remington UMC from a mega pack mostly with a 115 grain weight, and on the second mag, a Promag, I experienced a failure to feed where the slide got hung up on the round still in the mag. OK, whatever. I sent the slide forward and take the shot. It felt limp and the gun suddenly lost weight. I look down and all the remaining rounds are all over the bench. The gun is still perfectly fine and functioned with my remaining KCIs flawlessly. My Glock has never had problems unloading any particular brand of ammo, load, or grain weight found on factory shelves.

Since the gun was perfectly functional after the fact I can only assume that it was either the mag or ammo...both of which I am now finding out, have bad reputations. What are your guys thoughts???

I was not aware of the ammunition's reputation when it was purchased. That said, at the time of the malfunction, I was officially halfway through the box, all of the ammo through this same Glock, as it is my only 9mm pistol. No malfunctions before this. Everything seems to be pointing to the mag. That said, and this being my only promag, I have been using it for over a year without problems...did it finally just reach a breaking point?

Exactly right, the floor plate blew out. I just drew a blank and couldn't remember what the darned thing was called. Up until some of the reviews I've read I thought Promags were good. Never again. I plan to stick to OEM mags for the Glock from now on.

The Magpul was a gift for getting away from a 10 only round state. The Glock was my first handgun and I was still getting into the whole "gun" thing. I was amazed to find out you could have more than 10 rounds. I got all three KCIs used for $15 from a friend who sold his gun. He had hundreds of rounds through each of them with no malfunction or modification needed. Having the history behind them I felt comfortable buying them, and the price was a steel. I have had similar results with them and I trust them enough to carry with the 3 that I own. Any additional mags from them would be heavily scrutinized and probably relegated to range use. I will admit that they are a little bit harder to load, a spring replacement might help, but they work just fine and I 'm not going to fix what ain't broken. The R,W,&Bs I bought during a craze from CTD for $11 each because the OEM 33 rounders were just not available. I had no idea that we were in a buying craze, or what that even meant. I just knew that I wanted some 33 round mags to hang around the home for training and range purposes and those were the only ones I could find with any measure of affordability. I don't use them terribly often, but I have yet to have a malfunction with them. However, I will be investing in some OEM mags in the near future of both capacities.

anyway, I will be staying away from anything Promag...Lesson learned. I might try some Magpul as I am impressed with their AR-15 mags.