I disagree on that point. They very often look terrible. Having actors fake recoil is usually hit or miss as well.
But if movie studios and propmasters can’t be assed to take it seriously, then maybe that’s the only option.
Still we went like 30 years between incidents. That’s a pretty decent track record.
My understanding is that live rounds made it into the gun. Basically the prop guys were making blanks from live rounds and lost track of some live rounds. Maybe I heard it wrong.
At the end of the day either something in the barrel or live rounds, the person in charge of those firearms is responsible for things not happening. I can almost guarantee this is the result of someone getting complacent or not taking it seriously enough.
Edit: We’re both right.
In the film shoot preceding the fatal scene, the prop gun, which is a real revolver, was loaded with improperly-made dummy rounds, cartridges from which the special-effects crew had removed the powder charges so in close-ups the revolver would show normal-looking ammunitions. However, the crew neglected to remove the primers from the cartridges. At some point before the fatal event, one of the rounds had been fired; although there was no powder charges, the energy from the ignited primer was enough to separate the bullet from the casing and push it part-way into the gun barrel, where it got stuck (a condition known as a squib load). For the fatal scene, which called for the revolver to be fired at Lee from a distance of 3.6–4.5 meters (12–15 ft), the dummy cartridges were replaced with blank rounds, which contained a powder charge and the primer, but no solid bullet, allowing the gun to be fired with sound and flash effects without the risk of an actual projectile. However, the gun was not properly checked and cleared before the blank round was fired, and the dummy bullet previously lodged in the barrel was then propelled forward by the blank and shot out the muzzle with almost the same force as if the round were live, striking Lee in the abdomen.
Basically they made the dummy rounds from live rounds, bullet got stuck in chamber bad dummy round got struck, blank was loaded, bullet stuck in barrel became a real bullet again.
All things that should have been caught by the guy in charge of said firearm.