This reminds me of the story of the professor who runs into a math class this morning and says, “The most incredible thing just happened to me! I was driving to work and I saw this license plate - 2RDQ8193. Do you know what the odds of that happening are?!?!?”
Speaking of mortars - I’ve seen plenty of videos of mortar crews firing round after round without making adjustments. I assume the tube moves a bit with each shot but at, say, 1000 meters, how spread out will those rounds be at impact?
250m over 25km is 0.6°, not 0.06°.
So it is.
I typed in 25 instead of 250.
I guess that means it’s a piece of cake…
If we were to express artillery accuracy in the same terms as gun accuracy, how many MOAs would a modern 155mm howitzer shoot?
Is it common for anti-air or armor to be able to fire in indirect mode? For example, the Bradley’s 25mm seems like it could pepper an area with a lot of shells effective against infantry and unarmored vehicles even if it may need to get on a slope to get enough elevation. Anti-air vehicles don’t have that problem.
Has someone tried using the Mk 19 in indirect mode?
A degree has 60 minutes, so assuming the math above is correct, 0.6 degrees would be 36 MOA. But I don’t think it’s even useful to look at it like that. Especially when you consider that the 250 meter answer I gave earlier was for first shot accuracy. Once the gun is adjusted to the impact of those initial bracketing rounds, so that you know exactly where and how the rounds are hitting, you can expect to put all of your follow-up shots within a much smaller circle. When you call “Fire for Effect”, those rounds will be impacting within 50m or so of each other. That’s a lot more accurate than that 0.6 degrees given earlier. It has amazing repeat-ability, but the initial aiming process to get there is so much different than other system where MOA is meaningful. Imagine a rifle where you could never quite hit a bullseye without firing a couple rounds first, and then adjusting. But then, being able to hit bullseye after bullseye after adjusting your scope. But then you have to do that again every time you shoot at a different target; sometimes even the same target on different days.
I’m not sure what you’re getting at here. The 25mm HE rounds do kind of lob a bit, compared to the AT rounds. But no, they wouldn’t be used for indirect fires.
Sure, the MK19 can be used for indirect fires. BUT, the T&E mechanism and tripod is not designed to support this. It can only be elevated to effect its maximum range of 2212 meters. That’s technically direct fires on an area target, but it’s still one hell of an impressive lob. The flight time takes forever. I once gave my MK19 gunner the go ahead to engage an enemy rocket team we lased at 2100 meters away! They were on top of a hill, but on the near and far side of the hill was all villages. Shooting short or long would not have been good. We he let off those initial rounds, it felt like the were never going to land. They were in the air so long, I started doubting and thinking maybe they went over the mountain… shit, they’re going to land on some house or some yard. They finally impacted in the immediate vicinity of the rocket team; close enough to make a slight adjustment and fire a bunch more. Shooting at that distance is kind of like indirect fires, but technically it isn’t.
I would think the big difference between gun vs artillery is, the accuracy and consistency of artillery shell’s initial speed is at least as important as the aiming of the barrel. The shell is travelling in a tall arc, so the distance it travels is more or less proportional to the muzzle velocity.
It is a crucial component of the aiming process. The shell’s initial speed is variable. The firing solution requires a specific charge for the round. By increasing or decreasing the charge, the gunners can increase or decrease muzzle velocity. There is often more than one combination of barrel elevation & charge that will result in hitting the target. Often, there are several. This can enable a skilled crew to fire several rounds from one gun which all impact the same target at the exact same time.
They don’t really move if set up properly once you set/sink the baseplate. (Video)http://https://www.youtube.com/watch?v=U6u9VMDjckE After that the baseplate is broad enough to disperse the force without significant changes. Vehicle mounted mortars like the the M121 120mm mortar mounted in the M1064 (variant of the M113) don’t suffer from that problem.
I did once see what happened when a 60mm mortar was not set up properly during a hasty shoot at a target with direct line of sight. I was standing maybe 10-20 feet away from the mortar position. They hung the round. Things sounded …different. Then I noticed the tube was pointing close to straight up the and Brigade CSM was rapidly walking away from the gun. I followed. 
That round landed maybe 200-300 meters away. It was a training round with no HE filler. I still didn’t want it falling on my head. I will also confess to not thinking about what type of round it was as I followed the CSM.
Is that true of the Mk19? Or are you speaking about “proper” artillery now? I’d heard about the multiple rounds trick but didn’t realize it involved altering the propellant charge. How easy is that under battle conditions?
No.
He was.
Not easy. Every round involves setting the charge and the system involves checks. It’s still easier to not manage the different charges and gun setting for every round. Improvements in digital fire networks and supporting computer systems might make it easier. Most of the work on that capability has been countries fielding self propelled systems with liquid propellant and the gun doing most of the adjustments. In those cases it seems to be relatively easy.
With the giant caveat that my fire support experience was when there was still a Soviet Union. After that, I was a lumpy-headed tanker with extra experience that helped me better interact with the actual artillery troops to get the effects I needed.
Well, yeah, except as far as “you make your own luck” goes. A less skilled crew wouldn’t have had nearly as good a chance of that lucky shot.
Coming from a Marine in Vietnam this would be my answer. Calling in a fire mission in Vietnam consisted of giving your coordinates (a 6 digit number which was by necessity inaccurate up to about 50 meters), the compass heading to the target and the distance to the target. All Three could be wrong. Some people were just better at it than others. The first shot would be white phosphorus which made an easily seen white cloud. Then you’d tell them, for instance, “Left 100 meters, add 50 meters.” They’d adjust and try again.
The only coordinates given were your position. That way the artillery knew what direction you meant when you said, “Left 100 meters.”
As I understand it things are quite a bit different today. GPS is accurate to within a few feet, so you know where you are. They have range finders so the distance to target is pretty accurate. The compass heading is the easiest part.
And I greatly expect that artillery is just more accurate than it was in my day where, with perfect information, accuracy was only within 50 meters.
So I’d say that today they are very accurate.
Once in November 1969 in the Que Son Mountains southwest of Danang my platoon was fairly well lost. It was the monsoon and raining several inches a day and we were in heavy forest. Our platoon commander had artillery fire on a point he was sure that we weren’t in. When it hit he could got a general idea where we were.