Hello, I don’t see a lot of resources for sniper gun injuries, especially that of .50 cal rounds. I have a character that had the bone at her lower leg (near the ankle) shot by a .50. How bad would the damage be when compared to the same bullet actually hitting the ankle bone or the leg muscle?
So, there’s a weirdness with the .50 round: It’s not supposed to be used for precision shooting. It is used that way. There are many precision rifles chambered to various 12.7mm cartridges, including the .50 BMG. But, they’re not really intended for use on people.
(To be clear, every time I’m talking about a .50 from here on out, I’m referring to the 12.7x99mm rifle cartridge. Incidentally, if you were to simply search for .50 wounds, you would probably get a mix of rifle and pistol wounds, since there are many distinct 12.7mm rounds in circulation.)
The .50 BMG was originally designed during the First World War, with the intention of use as an anti-aircraft round. These entered service in the ‘20s and saw extensive use during WWII as an anti-vehicle round. This is it’s intended role, even today.
In the early 80s, someone got it in their head to build a precision rifle around these things. The result were firearms like the Barrett M82. This 30lb monster is, probably, the rifle you’re thinking of.
Thing is, these rifles fire a round that was intended for taking out vehicles, not people. As a result, they’re designed to deliver a terrifying amount of force to the target. The point is you put one of these into a truck’s engine block to kill it. Which doesn’t work 100% of the time, but a few extra hits will usually get the point across. You put one of these into a person, they’re done.
I don’t have hard data on what these things will do to a person. There is an inaccurate myth that near misses can kill from the atmospheric shockwave alone, which isn’t true. There’s also stories about these things taking limbs off on a hit. Based on what I’ve seen with these rounds and ballistic gel tests, that seems credible. Put one into someone and you could easily end up looking at an eight inch exit wound.
Connecting with the ankle probably means the foot is gone. I don’t mean damaged irrevocably, “we’ll need to amputate.” I mean, anything below the point of impact is missing.
Traditionally, precision rifles used against living targets is chambered somewhere around .30. The classic examples are .308 and .30-06, though there are others, and I’ve heard good things about 6.5mm rounds. Even then, a shot to the ankle means your character probably isn’t walking again without reconstructive surgery. A shot to the bone will break it. A shot into the meat can cause some serious tissue disruption, but assuming it doesn’t nick something important, and the impact didn’t fracture their leg, they should be able to survive.
The use of a .50 rifle as a sniper’s rifle is for extremely long range shooting. These are the guns you break out when you need to hit something over a mile away. If you have a character that needs to put assassinate someone riding in an armored Limo, a .50 will do that. If your character needs to put a bullet in someone from the dark side of the moon, then the .50 is the right choice. Because, if it connects, there’s very little risk of the target getting back up.