Answer by Chris Smith,
I worked in the ER of a level 1 trauma center for several years, and I've seen a LOT of gunshot patients ... including people shot with a .45. I am also a certifiable gun nut who owns and shoots (and carries) several pistols in .45 ACP.
First of all, let me clear up some misconceptions about what happens when a pistol bullet hits a person ...
- It does NOT knock the person over backwards. Even rifle bullets don't always do that, and they are FAR more devastating than handgun bullets.
- Shot placement is KING, even with hollowpoints. If you don't hit a vital structure hard enough to collapse the target's systems, they may not be stopped right away.
- Roughly 80% of gunshot patients survive their injuries ... even if they don't get medical help right away. A significant percentage of those that don't survive will die of blood loss or wound infection, rather than from the damage to internal structures caused by the bullet.
- There are many MANY documented cases of people soaking up multiple bullet wounds who keep on fighting. This is because there are TWO types of incapacitation: physical, and psychological.
- Physical incapacitations are due to damage to critical structures necessary to maintaining life. They include sudden catastrophic loss of blood pressure (perforated aorta or femoral artery), catastrophic CNS damage (brain/spinal cord injury), and catastrophic skeletal failures (femoral or pelvic fractures, for instance). BUT ... being shot through the lungs, or through the bowel will not necessarily physically incapacitate the person who is either determined or psychotic and wants to rip your face off.
- Psychological incapacitation occurs when the gunshot person is either too frightened or in too much pain to continue the fight. The psychological impact of getting shot cannot be overestimated. People get shot, and they either assume that they cannot continue or that they are going to die, and they just give up. That is one of the reasons that training is so important if one is going to be exposed to the possibility of getting shot at. A very large part of surviving getting shot is being trained to keep your head about you and staying focused on the task of survival. (My dad was shot in the chest on Iwo Jima, with a rifle bullet, and he stayed in combat for 48 more hours before getting any treatment beyond some morphine, sulpha powder, and a field dressing until he was able to get back to the American lines. Psychological incapacitation was not a luxury that the wounded could afford on that day.)
There was a time when the terminal ballistics of .45 ACP were much better than with 9mm, but that was not because the .45 was so good, but because the 9mm wasn't. This is not so much true any longer with modern powders and bullet design. They are just two ways of getting to the same place: small and fast, or fat and slow. But consider this: a .45 caliber bullet is the metric equivalent of 11mm. That's right, just 2mm larger in diameter than a 9mm. Go get yourself a metric ruler and see how small a difference in diameter 2mm is. THAT is why there is not much difference in the wounding potential of a 9mm versus a .45 ACP.
Also, "point blank" does not mean "contact distance" as some think it means. The term point blank would describe that distance out from the muzzle which is close enough that there has been little or no practical degradation of ballistic performance. For a handgun, that might mean 4 or 5 feet, or even further depending on the caliber. For a rifle, "point blank" might mean 15 or 20 yards or more. So I am going to assume that by "point blank" the original poster means "contact distance," which could be defined as that distance as which the muzzle is within a few inches or less of the target. Example: Jack Ruby shot Lee Harvey Oswald at pretty much contact distance.
So, with all of that said, there would be several types of injury occurring at contact distance. First and most externally obvious besides the entrance wound itself would be what is called "stippling," which is type of tattooing caused by still burning or unburned gunpowder residue which follows the bullet out the muzzle.
At contact distance, a large of amount of the gas ejecting from the muzzle would follow the bullet into the body. There might easily be some scorching of the edges of the hole, and the same particulate matter that causes the external stippling would also be blown into the wound.
Next is the foreign matter carried into the wound path from clothing. The bullet itself is fairly sterile ... perhaps not completely so, but the combined forces of heat from the burning charge and the friction of the bore on the bullet's shank would probably come close to sterilizing it. However, any bacteria contained in the fibers of clothing or growing on the skin will be carried into the wound channel. In fact, even if no vital structures are hit and there is minimal blood loss, there is still a very high risk of wound infection, and treatment would necessarily include IV antibiotics.
Hydrostatic shock as a wounding mechanism is often overstated, but it does exist. However, it is as much a factor of the velocity of the bullet as it is the diameter (the .45 ACP bullet is relatively slow) as well as it is a factor of the type of tissue through which the bullet is traveling. The hydrostatic shock causes the tissues along the wound path to stretch away from the bullet's passage, much like the wake of a boat in water, causing a temporary stretch cavity. This cavity collapses back in on itself almost immediately. The myth is that the stretched tissue is torn apart. The truth is that tissue is elastic, and it is stretched and then rebounds to its original location within the body. The stretching may cause some bruising of the tissues, but the actual shock wave itself does not disrupt tissues.
The principle method of wounding is the crushing of tissue in the path of the bullet, and this is called the permanent wound cavity. Since FMJ bullets do not expand in diameter upon impact, the destroyed tissue would be limited to the path of the bullet, and only slightly larger than the actual bullet diameter. Sometimes bullets will yaw (turn sideways or end over end) after impact, and that can affect the size of the permanent wound cavity, but not by that much. If an FMJ bullet encounters bone, there is a significant possibility that it will either break the bone if it is a long bone like a humerus, or punch through the bone if it is a flat bone like a rib or scapula (or skull). There is also a significant possibility that bone will deflect the bullet off of its original path.
Finally, FMJ bullets tend to penetrate more deeply than do hollowpoints. When a hollowpoint expands, the petals act as a sort of parachute in the tissues and slow the bullet down more quickly. Unless the affected body part is an extremity, there is not likely to be an exit wound with a hollowpoint bullet. But FMJs will often exit the body, producing an exit wound of near equal diameter to the entrance wound. It can actually be hard to tell them apart sometimes if the bullet is fired from further away than contact distance. This tendency to produce an exit wound is called "over-penetration" and it is why an FMJ bullet is not a good choice for home defense. Once it has been fired, it cannot be recalled, and if there is someone or something precious to you beyond the "bad guy," he/she/it may be destroyed in the process.
This tendency to over-penetrate means that unless the bullet has hit a vital area so as to cause rapid incapacitation, the primary means of incapacitation will be blood loss. Two holes means more blood loss than one.
This is anecdotal, but I have personally held a conversation with someone who was shot right through the heart with a 9mm FMJ, before we took him to surgery. He was alert and oriented to time and place, and very much alive. Surgery saved his life, but being shot in the heart did not produce instant incapacitation.
So, with regard to the specific question of "what kind of wound is likely to be caused if someone is shot in the upper arm or shoulder with a .45 ACP FMJ," it would most likely be a through and through with a fairly unremarkable exit wound. At contact distance, if the bullet encountered bone, the bone would almost certainly be smashed by the bullet. If "shoulder" includes the area near the terminus of the collarbone, there is the possibility of a pneumothorax (collapsed lung). If the bullet hits the brachial artery in the arm, there will be dramatic blood loss, requiring the application of a tourniquet to prevent exsanguination. It if hits the subclavian artery (beneath the collarbone) there will be dramatic blood loss. If the bullet hits the joint between the humeral head and the glenoid fossa, it will severely damage the joint, possibly requiring replacement/repair. If it is a simple through and through with no structural or vascular damage, it will be a fairly easy thing to recover from.
Meaning no disrespect, but the question is kind of like asking, "what does a sandwich taste like?" There are so many possible variables that it is impossible to give a simple answer. But trying to make it as simple as I can ... if the bullet does not hit a major artery, the wound is quite survivable, and would not appear that dramatic to an observer.