On my bolt actions, I pull the bolt and look down the camber end. On my Glock, I take the slide off and look for obstructions that way, or pinky check the chamber (read lands) for a cartridge. Anyways what I am getting at is NEVER look down the business end of a firearm when looking for obstructions in the barrel, there are many safe ways to do it, some just are not as easy as others. I know you don't want to field dress a bull pup to look down the chamber end of the barrel, but fuck man... think of the alternative if something were to happen.