How Effective Were Civil War Rifles?

The armies of the American Civil War fought (mostly) with muzzle-loading rifles.  The expanding Minie ball allowed muzzle-loaded rifles to fire at the same rate as smoothbore muskets.  Rifled muskets had existed for hundreds of years previously, but rifling required a tight seal between bullet and bore to work and so loading a rifle meant hammering the bullets down inside instead of just dropping it.  The Minie ball fell freely down a rifle barrel, then expanded against barrel grooves when fired.

This made bullets more accurate.  How much did this contribute to the bloodshed?  In Battle Tactics of the Civil War, Paddy Griffith proposes that it made little difference.  Griffith’s overall thesis is that the Civil War was the last of the Napoleonic wars, not the first of the modern wars.  Regarding the alleged impact of rifled muskets, he basically makes the following claims:

1. Increased length of battles, not improved weapon effects, drove casualty rates.  Civil War soldiers didn’t die in such large numbers because rifle fire was more lethal, but because because they fought longer.

2. Documentary evidence, while sketchy, suggests that the actual engagement range of Civil War rifle infantry units was no higher than of Napoleonic smoothbore infantry, and this fire was no more effective (see above).

3. Whatever the theoretical capability of Civil War rifles, soldiers lacked either the training or experience necessary to exploit it.

Chart from Griffith’s book comparing the Civil War to the unquestionably “modern” WWI and Napoleon’s campaigns.

These assertions might be true.  The rifled musket didn’t need to significantly improve the killing power of infantry fire to have a tactical effect.  I believe that above any improvement in killing power, rifles enabled Civil War units to deliver suppressing fire effectively in a manner that was not possible with smoothbore muskets.

Griffith’s Assertions Are Not Ridiculous

I have this rifle, an M1903, sighted at 100 yards.  I fire at a target 400 yards away.  Based on intuition, how far does the bullet fall below my sight?

For the standard-issue M2 Ball at 2800 fps muzzle velocity, about 34 inches.

(Modern 150gr loads are hotter and charts indicate a typical drop of ~21 inches; the M2 Ball’s trajectory more closely approximates 180 grain loads.  This is why all those CMP M1 Garands come with a warning about ammunition, and why you should heed them).

Before going on, I want to note a few things.  First, the overwhelming majority of hunters in my experience refuse to fire at anything over 100 yards away.  There are some good reasons for that but keep it in mind — and these hunters are using weapons very similar to the M1903 above.  Second, one of the biggest breakthroughs in infantry tactics consisted of people noticing in and after WW2 that the actual engagement range of a rifleman was no greater than 400 yards.  Again, using a high velocity weapon.

The M1903 is far beyond the state of the Civil War, where the most common rifle was the Springfield 1861 firing a 500gr round at 1300 fps (ballistic coefficient estimated at .160).  This calculator gives a drop at the 400 yard “maximum effective range” of over 17 feet for the higher-end velocity of 1300 fps.  For a still-in-spec 1000 fps velocity, the drop at 200 yards is nearly 4 feet, meaning a good center-of-mass shot at this range will probably end up in the ground.  Even most “experienced” hunters probably were not really aware of how far their bullets fell from the point of aim at this range, beyond “wouldn’t expect to hit an animal”.

Griffith’s other major assertion here regards training standards.  Recruit training focused almost entirely on drill rather than marksmanship.  Many, maybe most, soldiers did not fire their weapons (or any firearm) until they went into battle; soldiers who did receive firearms training typically fired a single-digit number of rounds and, again, most likely did so in exercises emphasizing drill over accuracy.

It Didn’t Matter That Rifles Weren’t Revolutionarily Lethal

Griffith fixates on the tiny proportion of men on both sides specially trained for long-range marksmanship.  Unfortunately in doing so he makes the hidden assumption that soldiers were either trained sharpshooters (hardly any) or completely clueless.

Even in the hands of a completely clueless soldier, rifles probably did increase the actual lethal range of an infantry firearm against a point target from somewhere around 20-50 yards for smoothbore muskets to maybe 125 yards.  This was only for the first volley however; follow-up shots were obscured by smoke (virtually every primary source mentions this).  So units delivering an initial volley had some reason to hold fire on an advancing enemy until “traditional” smoothbore engagement ranges; indeed even modern riflemen may deliberately hold fire until this range in ambush.  Griffith correctly notes that fighting units were generally not actually scythed down by fire; he estimates that a regiment under fire took about one casualty per minute.  A unit in closed formation receiving a volley that dropped the entire front two ranks, Hollywood style, would almost certainly run or, at least, stop advancing.

Where this breaks down, I think, is in the effects of “long range” fire.  At 100 yards, smoothbore musket fire could be disregarded by disciplined men.  At 200 yards, it could be totally ignored and at 400 yards might as well be a suitor outside throwing pebbles at the window.  First, rifles would have made infantry units much better at skirmishing or harassing than smoothbore infantry.  Someone handy with a gun from their civilian experience could reliably kill at 100 yards with a rifle; not so with a smoothbore.  Further, even if fire at 200 yards was generally ineffective it would not be anywhere near so wildly errant as its smoothbore counterpart.  Even if officers rightly considered volleys at 200 yards to be a waste of ammunition, and most soldiers rightly doubted their ability to hit anything, potshots from a few experienced or confident men in a regiment could easily inflict casualties on a unit advancing in closed ranks, again something flatly not possible with older weapons.

So, the major contribution of the rifle to the Civil War may have been increasing the range of marginally effective (suppressive or harassing) fire rather than an increase in lethal range against exposed point targets.

This marginal as opposed to revolutionary increase in effectiveness makes sense given that the rifled musket, while allowing some extended range, kept its predecessor’s rate of fire and blinding smoke.  Indeed, the fact that rifles did not take hold as infantry weapons before the invention of the expanding ball puts a hard limit on the rifle’s relative effectiveness: whatever the benefit of better accuracy, it wasn’t enough to compensate for a much slower rate of fire before the Minie ball.