south wrote:Is it always because of the powder charge being too light?
Or the powder charge being absent. The reloader (or the factory!) has primed the case but missed completely putting any powder in. The primer fires with enough force to push the projectile into the bore but not to exit the barrel. The next properly filled case with primer, powder and projectile causes a kaboom.
This is why there are minimum loads, even for light Trail Boss type loads.
Or if you are lucky and the loads are light the projectles get stuck but there is no kaboom - the lesson is if you are firing light loads, the shot feels odd, no impact on target or odd recoil - check the bore!
http://www.thefirearmblog.com/blog/2014 ... s-kabooms/