How harmless or lethal are blanks? Would they still hurt you if you were to fire them from a close enough range at someone?
It depends on the ranges, but blanks can kill.
So, when we’re talking about injuries and deaths from firearms, the focus is, somewhat obviously, on the bullet. That’s reasonable, the bullet is the most dangerous part of the equation, but it’s not the only danger.
Gunpowder doesn’t, technically, explode, it simply burns very energetically. This means there’s a lot of hot gasses, and burning particulate matter ejected from the barrel. Anything that doesn’t make it out of the barrel (called fouling) needs to be cleaned periodically.
This is an important, and often overlooked detail, conventional firearms are dirty and messy weapons. Modern powders burn cleaner than black powder, but this is still nasty, corrosive, stuff. This is why cleaning your gun is important, and why guns became significantly more mechanically complex after the invention of cordite. As well as after each new iteration of propellants.
Gunpowder at the point of ignition burns somewhere north of three thousand degrees Fahrenheit. (Above 1800C.) Now, it doesn’t stay at those temperatures for long, but it does release rapidly expanding, extremely hot gasses. Those can result in severe burns, at extremely close ranges (read: several inches.) Pressing a gun, loaded with blanks against someone and firing it will result in some pretty horrific wounds. This is because the expanding gasses will be forced into the victim, resulting in a star pattern tear in the victim’s skin, significant internal disruption, and burns.
Second, the bullet is not the only projectile a gun will eject. Wadding will also be sent down range. In the case of shotguns, wadding is critical for getting the shot moving. However, in the case of blanks, the wadding is vital for keeping the blank from simply dumping it’s load out the front of the cartridge. This isn’t usually much of a consideration because it’s fairly light weight, and doesn’t tend to go very far before physics catches up with it, but if you’re struck by it when the gun is an inch or two away from your body, it’s still moving quite rapidly, and while the mass is quite low, it will still have some significant force behind it.
All of this is short range, gunshot burns usually end around 3 feet from the gun, though stray particles of burning powder can travel father. So, generally, blanks are, “safe” if you’re more than a few feet from the target. However, for something like a mock execution (where someone puts the gun to the back of another’s head), they can kill.
Unfortunately, there have been more than a few on stage deaths that were the result of actors fooling around with blanks. One example is Jon-Erik Hexum, who started playing Russian roulette with a blank cartridge on the set of Cover Up. The blank blew a hole in his skull, and the resulting bone chip was forced through his brain, killing him.
There are other tools to simulate a gunshot at close ranges, but it’s not as simple as loading blanks into a functional firearm.
Also worth noting that blanks can propel debris in the barrel with as much force as a normal gunshot. The common example are some nail guns, which use blank cartridges to propel the nail into wood.
The more tragic example is the death of Brandon Lee. While shooting The Crow, Michael Massee’s character used a .44 magnum revolver (a S&W Model 629.) The gun had been loaded with blanks. For the scene where his character murders Brandon Lee’s. The problem was in the prop.
The 629 had previously been used in a series of close ups. The production had created dummy rounds, but dismantling live .44 cartridges, and removing the powder, then reassembling the bullets. This left the primers intact. Something that is not an issue with commercially produced dummy rounds, that exist specifically for situations like this.
After shooting the close ups, the prop master dry fired the revolver before removing the handmade dummy shells, and never examined them to determine their condition. There’s so many things wrong with this, but I’ll condense to the important detail, the primer for the round in the chamber migrated the bullet into the barrel where it came to rest. After that, without ever inspecting the barrel, or really examining the weapon, the prop master loaded it with blanks.
When Michael Massee was supposed to fire a blank at Brandon Lee, the bullet in the barrel was ejected, killing him.
Blanks still simulate a gunshot. It’s, “safe,” if you’re careful. But, get close enough, and these can do some singularly horrific things.
If the point of the question was, “can people screw around with them and live?” Yeah, or they can die. There’s a range of possible outcomes, few of them pleasant.
If the point of the question was, “is there any truth to that, the actor gets killed by a blank?” Yeah, that does happen. With just enough frequency to be depressing. Brandon Lee’s death was tragic, but the number of moving parts that created that tragedy was unusual. There are plenty of actors, like Hexum, who have killed themselves or others by mishandling props because, “it’s just a blank.”