I have never experienced any issues with my glocks ( I currently own 3 ) but have never witnessed, but heard from a credible source that there are some issues with hand loads and "lower quality" ammunition. The worst I have heard was a Glock 23 being ruined by a hot hand load of .40 cal. Didn't see it though. I mostly shoot 9mm out of 2 of my Glocks and don't have any hiccups. My Glock 23 doesn't have any terrible issues, but had a pretty bad jam when I fired some deffective reloads.
Just stick with the stuff in a box and you should be fine IMHO.