DF, it's true that very soft lead bullets (meaning swaged lead, not cast for the most part) don't do well in Glock barrels, but that's true for a lot of other barrels as well. Medium to hard cast bullets are a totally different story though; as long as the bullet is slightly (usually .001" or more) larger than the groove and throat dimensions and hardness is matched well to maximum load pressure, they'll generally shoot well in Glock barrels without any danger. Obviously there are exceptions when loads are too hot or too weak, bullets the wrong shape, etc etc, but again those things apply to pretty much all barrels, not just Glock.
I'm speaking from experience, cast being 99.9% of what I shoot, lots of it in Glock barrels.
One caveat/exception that specific to the 9mm though is the tendency for some European 9mm barrels to have larger groove diameter than the standard .355" in the US. I had one 9mm G19 barrel (Austria marked gun) that slugged at .357" - that would tend to lead up (obviously) with .356" cast bullets, but when used with the same bullets at .358" it had no problems. My other Glock 9mm bores have all been .355". That particular oddity of 9mm barrels seems to be a Euro vs USA thing and is not exclusive to Glock.
