What were you shooting for ammo? Some reloads are dirty (BULLSEYE Power) and it could had been some crud get thur the hand window and got on the hammer and stuck due to the heat in the gun.How hot did you get her? If it is a new gun and you were braking her in could be part of the problem. Good chance that it will do it the next trip out, if it doens't I would bet it won't do it again.