It can be bad because the forged alloy in front of the hammer was not designed to take the force of a hammer hit. It is very possible to break the lower receiver buy pulling the trigger without a stop block in place or the assembled upper installed. Check the area in front of the hammer for damage.
NRA Chief Range Safety Officer, Home Firearm Safety and Basic Pistol Instructor
"The democracy will cease to exist when you take away from those who are willing to work and give to those who would not."