There is a lot involved, but the basic idea is that your rifle and sight need to be calibrated to match from where you’re shooting to where you’re shooting. The journey to the sniper hides was long, arduous, grueling, and not exactly guaranteed to be hassle free. You might be stumbling over miles of dirt with stray wires, holes, dead bodies, broken equipment, rubble, and so on, at night, in pitch black. Then wandering through narrow trenches packed with people going both ways, again with dead bodies, stray wires, holes, and broken kit. There is a non zero chance that the scope you sighted in yesterday could get tapped or knocked, and it will be out of alignment by the time your arrive at your hide.

The use of debris was a simple way to sight in. You tell your spotter that you’re gonna shoot that tin can just by the sandbag over there. They tell you where you’re hitting so you can adjust your sights. Naive snipers would fall for this trick, but later on experience taught to use puddles instead.

Even modern day rifles need a handful of rounds to sight in. I assume due to the massive casualties suffered by both sides they were sending up troops to the trenches with little time to prepare.

Sniper rifles in ww1 where custom conversions of the standard infantry rifles or in the early war actual hunting rifles.

You can use a tool called a collimator to boresight a rifle in the field, but it's only so effective. And back then they didn't have technology like floating barrels.

Why didn't they shoot the other way to adjust their sights though? This feels like an obviously terrible idea?

I don’t believe there were very accurate rangefinders like we would have today so they really needed to zero their sights on the exact area they anticipated their targets being. They could accurately discover the range via test shots, adjust their scope, aka “zero” it. I don’t think they had mildots on their optics back then

> Why didn't they shoot the other way to adjust their sights though?

The other way? So at their own troops?

I mean... sure? Or to the side? Was it really so hard to find a large region in which there were obviously no allied soldiers? Like... people weren't wandering around outside the trenches right?

Another point, if you were a sniper, you would be sighting your rifle to specific ranges based on landmarks where you'd to see the enemy. So you're not just sighting your rifle, you are also figuring out approximate distances.

Ah, that's interesting. Didn't know that.

Yeah, there's a lot of math behind distance shooting. Tons of variables to consider.

If you want a walk down the maths involved - check out an app called Strelok (Pro) by Igor Borisov. I have no affiliation with this person or this app, other than I use it for extra-long-distance shooting calculations with a conventional rifle and/or air-rifle shooting calculations.

It's seriously astounding the math and thought that goes into shooting at long range. It makes me realize why I used to miss all the time as a kid; it's not just point and shoot.

If you're shooting far enough, you need to account for the Earth rotating out from underneath you while the shot is in flight.

You would definitely never shoot back along your own axis, or into your flanking formations. You just can't have enough situational awareness on who may be there. This is such an absolute that even when prosecuting an active firefight you would ask for permission to fire cross-boundary.

Maybe my imagination isn't up to snuff here, but I'm imagining not an active firefight, but a sleepy waiting game in the trenches.

Why can't you have the situational awareness that nobody is there just by looking with your eyes? Are you saying that risk of shooting objects on your enemy's side and giving away your position is lower than the risk of accidentally shooting someone on your side when firing at a rock in an open field? It just... doesn't make any intuitive sense to me.

You need to keep in mind the distances here. For calibrating your rifle you're shooting at targets several hundred yards away, making it much harder to tell if the area is clear. This also isn't happening on a football field, the area around the trenches is going to be scored with secondary trench lines, foxholes, communications trenches, big craters from artillery, etc. And the people in there aren't exactly trying to make themselves known, they are going to keep low and you may not even be visible if they are in a little offshoot of a trench or something. The secondary lines are also going to be relatively densely populated. Odds are if you try to shoot at a target a couple hundred yards behind the trench lines, the round is going to be within a dozen yards of someone's head. You probably wouldn't hit anyone, but if someone stands up at the wrong moment... an even bigger danger is if your shot goes high. If your shoot goes above the rock you're aiming for, it will keep going further back into the lines. Given that this would be 30 caliber ammo and there's no body armor, that bullet would still be going fast enough to kill someone 1.5 miles out, maybe 2 miles. Someone very familiar with the area and with good situational awareness might be able to guarantee there's no one between them and the target, but not for a mile out.

The other big factor is what your buddies in the trench will think of this arrangement. If they know it's you shooting over their heads they will be absolutely pissed, and probably face some sort of discipline from officers. If they DON'T know it's you shooting in their general direction (which they probably won't unless you make sure to tell everyone in advance) it will probably prompt return fire. If they can tell from the sound or muzzle flash that the shot came from their trenches, they may think a sniper infiltrated their lines, which will merit a particularly aggressive response.

I wouldn't be surprised if someone, somewhere during the war did this, but it certainly wouldn't be condoned.

> Why can't you have the situational awareness that nobody is there just by looking with your eyes?

The entire setup of an army, all its communication mechanisms, and systems of control and safety measures, are focused on telling you about what is happening forward along the axis.

Trying to figure out if it's safe to fire backwards is going to be massively error-prone as nobody is set up to tell you this and asking it is going to cause massive confusion.

Also, you can hit things that you can't see, with ricochet and fall of shot.

Hmm, I'm not militarily experienced obviously, so I'm not going to push this any more. I guess my last statement is that I believe you're correct, but it still seems like the creation of an additional system to safely designate a calibration target would be beneficial, especially to the side. Giving away your position sounds more error prone.

Other comments about what calibrating actually means seem to have filled in that missing intuition though.

Are your questions also coming from a standpoint of modern tech. such that a sniper could accurately measure range using a modern rangefinder?

This was circa the 1916-1918 time-frame. Modern range finding equipment did not exist, and what did exist at the time very likely required someone carrying a rather large range finding target over to the enemy lines to use to determine range (with the obvious negative result to that poor individual).

With no easy way to determine range (distance to target) beyond eyeball estimates, the only real way to sight in the sniper rifle was by taking test shots at a target and watching where one's bullet actually lands as compared to that target.

As mentioned in TFA, the preferred target for sighting was a puddle of water.

Why not have a berm in the rear area that's designated for sighting in rifles? This is common in today's environment.

Because that only allows for you to sight in at that range.

Unless that range also exactly matches the range to the enemy targets, from your current nest, you won't be properly sighted in for your intended targets.

The ranges over which snipers make kills is sufficient that even a very small miss-alignment of the sights translates to a miss (often by many yards) at the target. According to Wikipedia [1], the sniper record is 3,540m (3,871 yd). That is 3.5km - imagine targeting something 3.5km away, firing, and having your shot hit the target.

Even in 1916, while sniper's may not have operated at 3.5km distances, they could easily have been operating across 500-1000m distances (the Wikipedia article lists a 1918 record of 1,280m (1,400 yd) or 1.2km). Even at those relatively shorter ranges, the margin for misalignment is still tiny. You have to actually sight the rifle in for the actual range, the actual elevation (whether you are shooting uphill or downhill) the current wind conditions, etc. And still hit a rather small target. Aligning to some other fixed berm will not be nearly accurate enough.

[1] https://en.wikipedia.org/wiki/Longest_recorded_sniper_kills

> Why not have a berm in the rear area that's designated for sighting in rifles?

Because they're using fixed (non-floating) barrels and they need to re-zero in the field and can't get back to a rear area to do that.

I dont understand. The entire point is to tune the sight to the range where the other trench is. How the hell would shooting in a random direction do anything useful other than tell the enemy where you are.

The wind conditions would have been different?

ditto!

edit: wow you made a new account just to tell me you thought my question was dumb

If this is your standard for terrible posts, you can't have been on either HN or the internet long.