Only a time bomb if you make it so. Any loaded firearm is a time bomb.There are those that think hunting with a round in the chamber is a time bomb. Getting in your vehicle and driving down the road is inherently more dangerous than using snap caps.

I work on a few shotguns evey once and awhile and it is heck of a lot safer to put a snap cap in the chamber and tst for function than a live round and I don't have to leave the shop to do it.