This question is based on a specific situation. In the movie “Annihilation” a small squad of 5 female soldiers/scientists is sent into this weird, dome-like thing to see what’s inside. At various times they are attacked first by a large alligator, and then a crazy mutated bear with a face like a human skull (I still have nightmares about that thing). In both cases they handle these critters with full-auto fire from what appears to be M4s. It looks like it takes about half a magazine to kill each animal. The alligator charges with its mouth open wide, and the shooter is firing right down the animal’s open gullet. In the bear’s case, the shooter is about 10 feet away firing from the side, and it shows most of the rounds traversing the entire width of the animal and going out the other side. It appears that at least one round goes through the animal’s head and that does it in, but it’s a bit unclear.
Is any of this realistic? Would an M4 on full-auto (or any gun in 5.56) have killing power out of proportion to the individual rounds? Could (presumably) FMJ 5.56 penetrate as portrayed, even a notoriously tough animal like an alligator?
BTW, “Annihilation” was a pretty good movie, but a serious mind bender.
Thanks for the reminder to see that Movie!
Army vet and long-range shooter here. Enough rounds of 5.56 will kill any living earthly creature. The question is how many rounds and how much time to incapacitate. Injured critters like to move, like real fast, so they are hard to hit after the first impact. I would never hunt* with a 5.56–not enough one-shot ability to kill as quickly and humanely as possible. 7.62/.308 will kill virtually any living creature with one shot in approximately the right place. However, those weapons are large and heavy and don’t have near enough the sex appeal of the M-4.
*I actually don’t hunt. I shoot gallon jugs of water at long distances. Clean-up is a heck of a lot easier.
Good thing it’s at long range. Those things are vicious when wounded.
This. If you put 15 rounds (half a magazine) of 5.56 into the center of mass of something, that thing is probably going to die. Whether it’s really quick or drags on for some time (perhaps enough to kill the shooter) probably depends mostly on where / what the shots hit.
Funny, this reminds me of a conversation I had with a Special Forces guy as we were looking at a pod (?) of hippos rolling around in a marshy area about how many shots it would take from his sooper special M4 to take down one of those beasts, had one started towards us. He said he would rather run like hell towards the truck and get out of there.
Later, we entered the truck and he couldn’t get it started because he wasn’t used to driving a diesel, and kept trying to engage the starter before the glow plugs warmed up. His buddy kept yelling at him that he was going to flood the engine.
I am pleased that the hippo did not, in fact, charge us.
It’s really easy to mortally wound something with a gun. It’s much harder to quickly incapacitate something. Likely, those animals were already done for with the first bullet… but they didn’t know it yet.
And of course, even once a target is incapacitated, it also takes some time for the shooter to know it. Which leads to the shooter continuing to shoot, especially when armed with a full-auto weapon.
Relevant column: Could I take down a T. rex with my Beretta 9mm pistol? - The Straight Dope
Supposedly the book mentioned has a chart of effective cartridges (elephant-gun type). As for smaller ones (5.56), the question is, can you put more than one on target.
First, I’d like to politely take issue with your choice of phrasing here. Why “female” soldiers/scientists? If they were men, would you have made a similar qualification? Women are fully capable of being either soldiers or scientists. No irrelevant caveats or qualification is necessary in the description. It is like saying the group consisted of five hispanic soldiers and scientists. Just saying they were soldiers/scientists is enough. Their M4s, bullets, and science equipment behave exactly the same way, regardless of their sex, race, hair color, etc.
More bullets is always better than one. To bring down the beast, you want to cause as much blood loss and/or nervous system damage as quickly as possible. The more bullets entering the animal, the more induced trauma, the greater the blood loss, and the greater the chance of hitting something critical–like a spinal cord, heart, brain, etc.
They would be using M855 or M855A1, both designed for penetration of hard targets and better at the task than an ordinary FMJ 5.56. With that said, I wouldn’t expect the rounds to be able to go through the full width of a large bear. 13"-15" of him, at most–especially through the shorter barrel of an M4. He’s probably at least twice that wide, right? It would be easily capable or penetrating his skull, though. Tearing up an alligator shouldn’t be an issue either. And again, one round is going to cause bleeding and possible a slow death. More rounds will cause more blood loss, more rapidly and one of them might finally take out the CNS or something. The goal is not just to kill it, but to kill it before it eats you. It’s possible to mortally wound the thing, but it dies after it limps away from your mauled body. You want to stop it before that point. So, yea, more bullets more fast. Full-auto would be the way to go, especially at such a short distance where your decreased accuracy will not reduce the number of impacts.
POSSIBLE SMALL SPOILER
Bear, I read the book but haven’t seen the movie so I don’t know if this plot point is carried over, but the team selected for this mission was specifically composed of all women, where others had been all men or mixed gender.
That’s not much of a spoiler, BTW, it comes up very early.
That is correct. The gender of the team is deliberate and the characters even remark on it. They are the last of many teams that have attempted what they are doing, and the main character (played by Natalie Portman) has volunteered to go specifically because her husband was in one of the earlier expeditions. Almost everyone else in all those other mostly male expeditions has died or disappeared. IIRC , it’s said that an all-female team is the one thing that hasn’t been tried. Portman’s character is a cellular biologist and former member of the U.S. Army, hence a soldier/scientist. She is, in fact, the one who guns down the alligator, demonstrating great coolness and firearms ability under stress.
How’s that, Bear_Nenno? Maybe don’t be so quick to make assumptions next time, eh?
None of that is relevant to your question. Your question was about terminal ballistics of the 5.56 FMJ fired through the 14.5" barrel of an M4 Carbine on full-auto. That has fuck-all to do with the sex of the shooter and any mention of it is sexist. Period.
Well by all means, don’t let relevant facts about the story interfere with your chosen mode of outrage. :rolleyes:
Isn’t the point that those facts are not relevant to the question?
But it was relevant in the story that spawned the question.
ETA: The question could have been asked without referencing the movie at all, but because the party composition was germane to the movie, and the movie was referenced as the genesis of the question, bringing it up isn’t sexist, just descriptive.
If you want to immediately incapacitate a dangerous animal with a gun, you need to study anatomy, not guns. Because you need to know exactly where the animal’s brain is.
This is how Walter D.M. Bell became so successful in killing elephants. He wasn’t an expert shot, nor did he use extravagant firepower. Instead, he became an expert on elephant anatomy, and he knew exactly where the elephant’s brain was:
He had detailed files.
I wonder if using tracer/incendiary rounds would do anything to frighten the ammo or possibly do more damage to it.
Tracer shots tend to make other ammo jealous rather than frightened, or so they say.
Have no idea the effects on animals.
Did some more reading. I was wrong about one thing: Bell was an expert shot. This, along with his expertise in elephant anatomy, allowed him to bring down elephants using rifles of smaller caliber than those used by his contemporaries.
Well Japanese World War 2 ammunition could not kill crocodiles, as one regiment found at during the Battle of Ramree Island.