Why did Civil War officers tell their men to "aim low"?

Seven decades of ignorance is not bliss. For most of this time, I thought that at least one factor involved in the aiming of small arms at knee level was a "negotiated protocol" among warring nations. However, I could not find any such protocol in a brief "search" of Geneva protocols, and I did not know what other "treaty" or "truce" protocols to search. I can imagine that my aiming method protocol was not highlighted or ingrained very much. Now I am wondering if my aiming method protocol between combat adversaries ever even existed.

I get the concept that wounding an enemy may take two or more enemy off the field of battle, at least for a while. I get that the knee level shot might kill the enemy anyway. I get the ballistic/trajectory factors. However, those concepts have little or nothing to do with making an established protocol effort that allows the ex-enemy (as well as our own ex-fighters) to return alive - albeit temporarily or permanently disabled - to families and, perhaps, to continue somehow to make a livelihood.

Bullets (and shells) of the guns of the day, had a tendency to "fly high." That meant that many of them missed the enemy. This was because of sights and "recoils" that caused bullets' actual trajectories to be higher than their "official" ones.

The purpose of "aiming low," was to compensate for this fact and improve the likelihood of hitting a man SOMEWHERE. The usual idea was to aim "waist high." Such a bullet might hit an enemy in the stomach, chest, or legs, depending on the trajectory of the bullet.

A bullet aimed at the face was more likely to kill someone if it hit, but also more likely to miss. From a military point of view, a chance of 2X of hitting (aiming low), which might wound OR kill, was better than a chance of X of hitting and killing.

As a practical matter, there were more men wounded than killed in battles. But unless the wounds were superficial, they were nearly as disabling as a shot that killed. And "disabling" was the point of inflicting casualties, so that the enemy couldn't fire back.

Everyone here has missed the mark...pun intended. It had nothing at all to do with kick, or trajectory. It had everything to do with the fact that your natural instinct is to aim center mass...the chest. Soldiers...and criminals...have been known to soak up many rounds in the chest and keep on firing. Then again, one round might get lucky and find the heart, or an artery. It is a roll of the dice, but the odds are not in the shooter's favor.

Here's a clue. Ever here the term "gut shot" and how it meant the situation was dire? The place you want to aim is the lower part of the body. Groin to belly button. The idea is to put the person down in one shot. One shot to the belly or groin will take a soldier out of commission, and as a side benefit, a shot that misses a little high or a little low, still has a chance. Remember Black Hawk Down, and the soldier who was shot in the leg and died? Leg wounds in video games are treated as trivial, but in real life, a gun shot to the leg can be fatal.

One issue which hasn't been mentioned is trajectory and correcting for terrain. If the target is above or below the shooter, this causes the round to hit higher on the target because the bullet is traveling at a slightly different angle with respect to gravity. This angle reduces the gravity drop of the round and makes the round impact higher. So, when correcting for shooting uphill and downhill, the soldier should always aim low.

.58 caliber black powder bullets do NOT shoot flat. If the sights are set for 3oo yds the bullets peak trajectory is 43" above the line of sight at 175 yds. (modern 5.56 mm only rises 3 inches when zeroed for 300 meters.)

If a soldier fires standing from the shoulder the rifle muzzle is already about 60 inches above the ground. If he aimed horizontally the bullet will rise to a point 104 inches (8'8") above the ground. Avg height for union army soldier was 5'8". If you aim between his feet and knees the bullet can rise 43" and you still have a chance to hit him in the chest.

Check out Cadmus Wilcox book Rifles and Rifle Practice. Professional officers knew about ballistic trajectory.

I agree with point 1 on the third answer - it was because of the kick on the musket that would send the ball too high if aimed horizontally. By pointing the musket down slightly from horizontal the kick on the musket would bring the ball slightly higher than horizontal which with falling trajectory would have a much better chance of hitting 'a target' in a group of men.

Let's not forget here that smooth wall (non rifled) muskets of the type used early on in the Civil War were notoriously inaccurate when fired from any kind of range. From close range their inaccuracy didn't matter, from longer range it was more a question of luck whether you hit anything.

Think of aiming up or down hill in the extreme - that is, straight up or straight down. There is no trajectory. Sights are calibrated for horizontal flight. Any elevation or depression will cause you to shoot high if you use the sights. Ask any bowhunter who shoots out of a tree stand.

Having shot an 1861 springfield i have to say i believe that the kick is not really a factor. The normal non leaf sights left me shooting about 7-8 inches high at 50 yards so if i was aiming for center mass i would most likely miss a soldier all together.

If it was anything other then the sights i would have to say it would be trigger jerk and recoil anticipation causing a high trajectory but i really think the sights played a huge part.

In fact it is because of the ballistic trajectory that the soldiers were advised to aim low. If a soldier aimed too high (and this seemed to be the natural tendency, given the frequent admonishment), the bullets would pass over the heads of the advancing enemy.

See this wikipedia article on the Springfield Model 1861, and page 196 of Daily Life in Civil War America by Denneen & Volo.

I know this has been answered, but from an actual firing of multiple civil war muskets and rifles, practical experience does suggest that the recoil and close range <100 yards would cause an elevation slightly higher than aimed.

I personally found that I had to aim below the target about 7-8 inches and to the right about 3-4 inches to hit the inner circle or bullseye consistently. I use a Model 1853 Enfield rifle.

My 1842 Springfield musket (smooth bore) was pretty much all over the place, no matter how I aimed, thus the need for the 'buck and ball' typical load for this weapon. A 69 round and 3 000 buckshot created a nice 18-20 inch pattern at about 50-100 yards.

Just a little practical field conclusions I made...

This was an ongoing problem with musket armed soldiery; in the Peninsular and Napoleonic wars, in-experienced infantry often shot high, and given that Brown Bess was the standard musket for the British Army from 1722, presumably an issue at least since then.

As such I am doubtful whether the sights of Springfield rifles are a key factor in this problem!

At a guess I would pin responsibility on two factors:

1) If you don't allow for it, the recoil of a musket will tend to kick the muzzle upwards - an experienced soldier can ride the recoil and control it reasonably well, but inexperienced troops are likely to let it rise. If the muzzle kicks upwards, the bullet will go higher than you expected, and so inexperienced soldiers are likely to shoot high. This is going to be exacerbated by the twin facts that many armies did not practice musketry with live ammunition on cost grounds, and that even those which did usually practiced volley fire only, not target shooting, so there was no clear way to gain knowledge that you were shooting high before engaging in combat.

2) The unwillingness of most soldiers to personally kill when they do not feel immediately threatened. As researched more recently (an article reporting on it can be found here, most soldiers looking over their sights at a human being not already trying to kill them will feel a strong impulse to aim off, or close their eyes when shooting to give the guy a chance, or similar. Assuming this phenomenon held true 200 years ago, and I see no reason it should not, the most sensible way for a soldier standing in line, facing a line of enemies to his front, to deliberately miss is to aim up. If, however, all of his mates are keeping their weapons fairly low, aiming at chests or stomachs of the opposing line, he will look very obvious if he aims above their heads! So getting the whole formation to aim low could be a way of using social pressure to overcome the unwillingness to actually aim directly at enemy soldiers, and thus make more of your volley hit.