Accuracy limits of Victorian-era rifles

Question

I have a fictional character in 1870 who is a marksman of superhuman ability; basically, he doesn't need a sniper rifle with a telescopic sight, he is a sniper with a telescopic sight, and can get the maximum physically possible accuracy from any weapon.

Looking at the weapons available at the time, this one seems representative: https://en.wikipedia.org/wiki/Snider%E2%80%93Enfield

Effective firing range 600 yd (550 m)

Maximum firing range 2,000 yd (1,800 m)

I understand these two specifications to be, respectively, the range at which you can hit a man-sized target with reasonable probability, and the maximum distance the bullet will travel and still retain a lethal amount of kinetic energy.

I'm trying to figure out what would be the effective range of this weapon in the hands of a superhuman marksman. It seems to me the best way to approach this is to ask, what is the limiting factor on the effective range?

Is it the accuracy of a human marksman?

Is it random environmental factors like the wind, that a superhuman marksman could conceivably compensate for?

Is it some 'random per unit, but fixed for that unit' variation in the rifle itself, that the marksman could conceivably learn to compensate for?

Is it inherent randomness in the system, impossible to compensate for, that will limit the effective range to 600 yards regardless of the shooter?

Answer 1

Accuracy variables:

There are a lot of variables that are tricky to control for your super-sniper, mostly the quality of the industrial processes at the time. If he maintains his own gun-smithy, he may minimize but not eliminate these variables. The problem is that this kind of accuracy was simply not expected in the period, so manufacturing standards didn't generally measure up.

• Powder: The powder of these weapons is gun powder, which is variable in manufacturing quality, consistency, and storage. It leaves a residue in the gun, requiring frequent cleaning. The discharge leaves smoke in the air that obscures vision and interferes with subsequent shots. It also reveals one's position. Smokeless powder was invented in 1884, but is within the capability of people at this time to manufacture if the basic technique was known. In the novel The Guns of the South, time travelers introduce the idea of nitroglycerine to a Southern chemist, who then intuits gun cotton (nitrocellulose) smokeless powder.
• Primers: Primers were manufactured products, percussion caps, and the manufacturing quality was somewhat variable. Reliability is better than powder in pans, but is still not perfect. Even modern-manufactured percussion caps for muzzle-loading rifles are of variable quality and make such weapons somewhat unreliable.
• Bullets: Bullets by this period were mass-manufactured, but slight imperfections could introduce variation in the best ammunition. Rifling helps to eliminate some of this variation (imperfections in a spinning projectile are "averaged out" in centrifugation) and weren't overly significant for the average shooter. But for your guy? It could be a real problem. The bullets are frequently sub-sonic for most of their flight (although the muzzle velocities could be supersonic), and big. While accurate subsonic bullets can be made, it would be tricky to justify given the exotic metals and designs involved. Copper-jacketed bullets (improving velocity, preventing deformation, protecting barrels and reducing lead residue in the gun) aren't invented until 1882. The copper electroplating process, however, was invented in 1840 so copper jacketed rounds could technically be done in this period (but the process is nasty and involves cyanide).

Range:

So we get to range. Most modern muzzle-loading riles with scopes are not reliably accurate beyond 200 yards. Although you specified a breech-loader, the overall design tech is comparable for accuracy. I might suggest the Sharps rifle family of weapons for range and accuracy in a breech loader. I suggest the movie Quigley Down Under might correspond very well to your super-shooter (although this is a scoped rifle). The effective range of a sharps rifle is 1000 yards (the movie claims 900-1200, but that's 1890, using an 1874 version of the gun), and this is a likely outer limit for your shooter. The longest documented shot with such a rifle is 1538 yards. For a super-shooter, the 600-1000 yard range might be realistic. For 600 yards, most of this "effective range" involved a thousand guys shooting at another thousand guys and killing more by mass of fire. At the 2000 yard range, the relatively large size and low velocities of these bullets mean your opponents might get hit, but possibly not significantly injured. Little effort in this time is made to make bullets terribly aerodynamic.

So to get much beyond 600 yards, your marksman probably needs to be a gun smith, making his own custom powder, casting bullets by hand, prepping and making his own powders, possibly buying specialty percussion caps made for the royalty of Europe. Even then, the guns of this time are unpredictable.

Answer 2

Pretty poor

First, let me endorse the answer by DWKraus, which does a good job of enumerating many of the variables that will contribute to inaccuracy. There are a few additional points, however, that are too long for a comment on that answer:

Looking through various black powder shooters' forums and the comments about the Snider Enfield, a number of shooters are complaining of the difficulty of achieving even a halfway reasonable grouping. (Put "benchrest grouping with Snider Enfield" into your search engine and see what comes out - I went with "benchrest" to simulate a super-shooter with a perfectly steady shooting position.)

• One shooter was complaining of shooting 8-10" groups at 50 yards, another of 19" groups at 40 yards! The posters were experienced shooters, meaning that the rifles were wildly inaccurate with what was expected to be the correct combination of projectile and powder quantity. These results mean that even a skilled shooter with a Snider Enfield and sub-optimised ammunition will achieve worse accuracy than a mediocre or average archer!
• Another shooter was fairly happy with their benchrest grouping at 50 yards, as seen in the image here. (For those wondering about the size of the target who haven't scrolled down in the comments thread, the "black" is 200 mm across, which shows how big the holes are.) This accuracy is adequate, but really poor compared to even an average beginning rifleman with a modern rifle.
• It appears from the discussion that accuracy degrades significantly after every shot without cleaning the rifle due to the unpredictable consequences of residue from previous shots. So while it may be possible to shoot reasonably quickly with a breech-loading black-powder rifle, shooting accurately will be slow because it needs to be cleaned after every shot. Even a superhuman marksman should have a set of rifles and equivalent number of gun bearers to quickly clean them between shots.

At this point, the accuracy starts to come down to the exact abilities of the superhuman sniper:

• I am assuming inhumanly perfect muscular control and superhuman visual acuity, in other words every shot is as if from a benchrest and using a telescopic sight (if required). Looking at the linked image and assuming they can halve the grouping size with perfectly tuned ammunition (that is, all the variables DWKraus listed) and impeccable trigger release, call it a 6 cm grouping at 50 m with increase in group size proportional to the range.
• Superior vision and instincts allow for the wind variation at ground level to be identified and perfectly allowed for. Moderately believable, this lets the 50 m grouping be applied against stationary targets out to the listed "effective" range of 550 m, although at this range the ESA (expected scoring area) is 66 cm, which is wider than a typical man-sized target. Without this ability, the ESA will expand exponentially (not linearly) with range in windy conditions.
• Foresight (the ability to see into the future, not the sticky-up bit of metal near the muzzle) is required in order to hit unpredictably moving targets more than about 200 m away. If a target is stationary or moving predictably then no superhuman abilities are required, which is how snipers and hunters make long range shots in real life. Note that the Snider Enfield only has a muzzle velocity of 381 m/s (depending on the exact powder and projectile combination), so with air resistance it will be 2+ seconds for the round to get out to the effective range of 550 m - a lot can happen in that time.
• "Shooting omniscience" is required for shooting at longer ranges or achieving tighter groupings with the equipment available. The shooter needs to know exactly how each propellant charge is going to perform and how each microscopic piece of matter in the barrel is going to affect the progress of the round and the vectors of all the masses of air in the trajectory that the bullet is going to pass through (noting that the air many metres above ground level can be moving at a different speed) and how the bullet will behave aerodynamically at each point in its trajectory. (This is along with all the muscular control and perfect vision mentioned previously.) Note that if the superhuman marksman has this ability then he shouldn't be messing around with shooting things, he can throw dice with perfect knowledge of how they will land and make a fortune gambling instead.

In summary - ignoring foresight and omniscience, I would consider it believable for a superhuman marksman with perfect 1870 equipment to make headshots every time out to 150 metres on stationary / predictably moving targets and reliable chest shots out to 300-400 metres. He may get lucky at longer ranges but he may not - fortunately for him, he can claim what he likes and those without a telescope or superhuman vision will be unable to tell what happened at long ranges. If you give him equipment better than the Snider Enfield (eg the Sharps that DWKraus suggests) then modify ranges accordingly.

Answer 3

To get those long ranges your shooter will be shooting up at an angle.

AKA "volley fire". The Enfield had sights to facilitate this.

https://www.youtube.com/watch?v=CWOw9Q6bovs

But the thing that surprised me - really not much of an angle! This shooter states that his gun was at 11 degrees and that looks right to me. The target is 3000 yards away.

I wondered - suppose you elevated the barrel to 44 degrees. That would take the maximum height of the bullet 4x higher than it was at 11 degrees. Let us ignore wind resistance and consider only gravity. If gravity is what stops the bullet by causing it to run into the ground (and in the video the puff of dust suggests it was still moving fast when it hit) would the bullet travel even farther? I think yes - my triangles say 528 more yards for a distance of 3528 yards. That is just over 2 miles.

In any case, your shooter at maximum range would appear to be shooting at something in the sky. Which he is - the top of the parabola he needs to make with the bullet between himself and the far distant target.

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An interesting thing about the video is you can calculate the speed of the bullet, roughly. It is 10 second in each shot from shot to puff of dust. That means an average of 300 yards/second or 900 feet / second. Published speed of an Enfield bullet is 1300 feet / second. Assume 1300 at muzzle and average speed of 900. How slow is the bullet at the end? Math (or maths if an Australian is doing them) 1300 + x = 900 * 2; x = 500 feet per second at the end of the flight. Not as fast as a pistol bullet at 50 yards (700-800 fps) but I bet it would still put your eye out. And this guy is a supernaturally good shot.

Answer 4

By 1870, effective range of sharpshooting was about 1000 yards

This was pretty much as good as early rifles like Sharps rifle or Whitworth rifle could do reliably. General John Sedgwick was killed from about 1000 yards distance during American Civil war, but beyond that distance rifles of that era just couldn't be accurate enough.

However, in 1870s there was significant improvement in both rifle and cartridge design, which pushed sharpshooting limits up to about 1 mile (1609 meters).