My understanding, from a guy I trust as I'm not a Glock user, is that the factory Glock barrels don't have a fully supported chamber, making them prone to detonation if loaded with inappropriately hot rounds (this was several years ago, Glock could have changed the design). His advice was if you want to hand load for a Glock, get an after market barrel with a fully supported chamber. I believe Lone Wolf makes some like this (but do you own research as I have not looked into it in a while and I don't use Glocks).