Powder is hard to find. I started reloading to make some light loads for my Ruger LCR. Later, I made the mistake of shooting some of the reloads in a larger revolver. One went ‘poof’ instead of bang. Bullet stuck in the barrel. Thank God I stopped shooting.
Probably missed a charge, the primer is strong enough to force the bullet into the barrel then the next round blows the gun.
I’ve had it happen twice over the years, both times I avoided pulling the trigger on the next round. A piece of brass rod and a small hammer are pretty good medicine for the problem.