If dry firing your Glock was damaging, they'd be falling down across the globe. While I suppose it is possible, it appears to be very limited, isolated cases. I seriously doubt dry firing is the cause in most, if not all, cases it's been associated. I've only heard of it happening (on the internet forums, once including this one, which has been repeated in a lot of different places). I've handled, shot, owned and seen Glock pistols for more than 20 years. No, I don't believe the little (tiny) bit of hammering behind the breach is more punishing than the beating going on in front of it. Some firearms shouldn't be dry fired ever, for similar and different reasons (I repair a bunch of them, mostly shotguns, and .22 rimfire). Snap-Caps are a matter of choice or convenience for Glock owners/users, I think. If this were a real issue, you can bet every issuing LEO department would also be issuing Snap-Caps. Every Glock gets dry fired at one time or another, most of them a LOT. Not always for the purpose of practice, or anything specific. Try to disassemble your Glock pistol without dry firing it. You can do it (I've had to a few times), but it's hardly convenient, and wasn't designed as a regular practice.