I have a stock Gen 3 Glock 19 with a slide that fails to lock open after the last round on occasion, but (apparently) only with Remington 115gr UMC ball. Anyone have this? I asked about it on another forum and they directed me here. I use the two factory 15 round mags, and so far as I know it doesn't matter which mag I use. I keep fairly detailed range notes, and it only seems to happen with this particular ammo. It irritates me, but I suppose it isn't a big deal other than I bought this gun new and can't figure out why this should be happening. Any similar experiences or ideas? This is my carry gun, and this little issue is starting to nag at the back of my mind. Thanks.