Do we know the distance between Baldwin in the church pew and the camera (and victims)?
Why did he need to pull the trigger in a rehearsal?
He blasted her at near point blank range. That’s why Baldwin was covered in blood.
He was practicing quick drawing and firing the revolver at the camera. This would involve quickly drawing the weapon, cocking the hammer and pulling the trigger for a classic "quickdraw" scene that's in about 90% of all western genre movies. As I understand it, the gun should have been empty, not even blanks at this point, let alone live round(s).
The armorer and asst director both appear to have cavalier attitudes toward firearm safety, and had no business in their respective positions. The armorer allowing people to handle, load with live ammo and fire the weapons after hours and between scenes is unbelievable, but she seems more into being "cool" than being safe. Live ammo on the set? Her age and obvious immaturity were glaring warnings that she was unqualified. Also, why is an asst director handling and issuing weapons to actors instead of the armorer?
Seeing as Baldwin is the Producer, he is going to get murdered in the civil suits coming up, made even worse that he pulled the trigger. It's highly unlikely he will face criminal charges, but he will get soaked financially.