Got a Real-World Weapon or Armor Question? Mk. VI

[Grey Paladin]

Actually, I came here as a last resort I already tried 4chan for a long while. For all the bravado /k/ puts on they know absolutely nothing.

[SurlySeraph]

I consider Operatorchan slightly more trustworthy than /k/, though neither are the most reliable thing on the Internet.

Have you tried gun manufacturer's web sites? Or writing to them to ask if they'd be willing to send you information? You could also try emailing one of the numerous gun nuts that are easy to find online.

[Grey Paladin]

Haven't thought of emailing the manufacturers - good idea, although I doubt the military ones will reply. Gun nuts tend to be rather . . . 'unstable'; if you know where I can find some of the more reliable ones, do tell.

[Yora]

I worked on this very same issue some days ago. I have not kept any of my notes, but apparently the ranges in d20 modern seem to be quite accurate.

Due to air friction, a bullet slows down all the time it travels before it hits something and finally reaches terminal velocity, which is the same speed and energy it has when droped from a couple of meters height. Usually it would probably have collided with the ground long before that, but after some distance it lost enough power to be unable to cause any serious injuries when it hits a person. I found some numbers for that distance and it seems not too different from the maximum ranges for firearms in d20 modern, which is 10 range increments.
Of course, accuracy becomes increasingly worse at long distances, as the target appears much smaller and there's more chance that sidewinds will change the bullets path a bit. When using a d20 system, the d20 modern firearms seem to be a very good approximation of the real thing.

Another problem is that there are many different ways of measuring maximum distance. Often each company has its own system which can be very different from that of others.

[LurkerInPlayground]

The realism fetish rears its ugly head again . . .

[lsfreak]

This has some fairly useful information. It has an effective range listed for most weapons, though rarely says exactly what that means. Specific questions can likely be asked in the Realistic Weapons thread on this forum.

[Grey Paladin]

Stuff

Thanks for the info. My own research up to this point seems to contradict the d20 measurements being in any way or form accurate but other than that it confirms what I know.

Stop having fun guys!

Nah.

This has some fairly useful information. It has an effective range listed for most weapons, though rarely says exactly what that means. Specific questions can likely be asked in the Realistic Weapons thread on this forum.

Will give it a look. thanks.

[erikun]

Have you visited the Real-World Weapon or Armor Question thread? I found it hiding down on page 2.

Beyond that, I've heard (not actually studied myself) that most modern firearms are more accurate than their users, at least at close/moderate ranges. That is, a gun is going to fire at whatever you point it at, with the reasons for missing being bad aim, bad timing, or misaligned sights. I would assume that extreme sniper range would be more affected by gravity and winds, although I would take that range to be measured in miles.

But seriously, I'm sure the people in the weapons thread would be more help than I am.

[Roog]

I'm not sure if this is the right board but what the heck. I'm trying to write up a system to simulate more-or-less realistic modern firefights but my inability to find any solid data on anything but civilian firing ranges (all at very short distances, no less) blocks me at every turn. If anyone can link or direct me towards reliable sources I'll be very thankful.

Big Bang and Compendium of Modern Firearms (Edge of the Sword Vol. 1) both seem have the sort of information you seem to be looking for.

#Edit
Although its mainly weapon performance, rather than operator performance that they are focused on.

[RS14]

Remember that bench-rest accuracy is very different from accuracy under fire. For the former, you'll have plenty of luck at any firearms board--I'm also a member of The High Road, and many of the rifle shooters there should be able to give you a rough idea of what typical accuracy means. I'm sure there must be some who shoot competitively out to 1000m or more. Ask what a good/average group is at various ranges. Remember that .223 slows faster than heavier rounds, and most military assault rifles aren't shooting platforms of the same quality as dedicated competition rifles.

Accuracy under fire is more difficult. I don't know where you'd get that, though I imagine there are various reports floating around about wartime accuracy.

Why wouldn't you be able to possess declassified documents? I would assume that such documents could be possessed by anyone, without restriction.

You can probably work out the effectiveness of suppressive fire by figuring the typical cross-sectional area exposed, the duration of exposure, and using a normal distribution of shots across the targeted position.

[Cthulubot]

GURPS High-Tech has a fairly extensive chart of firearms in the back. Also somewhere in there is their system for givings GURPS stats to real guns; you may be able to reverse-engineer the stats for the weapons listed therein.

They also have some suggestions as to how much stress may affect one's accuracy. It's a bit different shooting at a deer, or a man rushing at you with a knife, than at targets.

[Darrin]

I'm not sure if this is the right board but what the heck. I'm trying to write up a system to simulate more-or-less realistic modern firefights

Didn't Phoenix Command already do this?

Never played it myself, but I've heard horror stories about the first three seconds of combat taking 6+ hours to resolve.

[RS14]

Also, if you look at casualty/round expended figures, you probably want to look to very small conflicts--individual firefights. Ignore e.g. vietnam wide figures, and look for accounts where individuals recount a) their unit size (squad? platoon?) b) clips/magazines/rounds they personally fired and c) total enemy casualties. Pick small engagements with little or no suppressive fire, to isolate the effects of aimed fire. Yes, such data should be rare. Sorry I can't help more.

Also, at typical engagement ranges, I suspect training and mental state will have more effect on accuracy than the individual weapon. Sure, a Garand is more accurate than a M4, but in medium range shooting while under fire, the theoretical differences seem unlikely to be apparent.

Edit:

Haven't thought of emailing the manufacturers - good idea, although I doubt the military ones will reply. Gun nuts tend to be rather . . . 'unstable'; if you know where I can find some of the more reliable ones, do tell.

In my experience, public ranges tend to have more morons than private ones, if you want to get your hands dirty doing research.
Forums with a base of older shooters, particularly those with competitive and/or legal sections, tend to be better than those that are all hardware and general discussion. Real shooters also tend to be more responsible than those who only play video-games.
A purely technical discussion should also avoid most of the politically enthusiastic.

[Zincorium]

Considering no one is going to be verifying the figures, Wikipedia should really be sufficient for examples of rounds and their velocity/weight for a given barrel length. They've got figures for anything outside really old or obscure guns.

Realism is something that should only be determined down to a certain fuzziness. You can shoot someone with a 30.06 out of a 24" barrel bolt action at 50 yards, or a .308 in a 26" barrel semiautomatic at the same range, and while the guns may differ drastically in appearance, weight, handling, cartridge selection, rate of fire, and so forth, no forensic ballistician is going to bet their job on determining which one was used.

IMO, focus more on how the gun is used- does it have a stock, are the sights properly adjusted for the range, is it braced with a sling or a bipod, and similar- because all of that added up has a *major* effect on the one thing that really makes a difference: hitting the target in a vital area. Split hairs on hydrostatic shock and weight retention after you've got a good system for separating a shot between the eyes and one in the meat of the arm.

[Stephen_E]

The question of the monkey and the hunter:

A hunter aims his gun at a monkey in a tree. At the same instant the gun is fired, the monkey lets go of the branch he was hanging from.

How fast does the bullet need to go to hit the monkey, assuming no air resistance, friction, blah blah.

That ones deceptive because aiming at something with a gun generally means allowing for gravity/range. At which point the monkey letting go DOES matter.

Stephen E

edit. I should have kept reading to see others had noted the srious flaw of the question.

[Grey Paladin]

Aside from more authentic sources, thats all I need. Thanks for the assistance.

[Storm Bringer]

speaking as a soldier, I can say that, in regards to the standards of shooting I am expected to meet, how you hold the firearm is much more important that what firearm you are holding. That is, vairation in body position, point of aim, and other 'human' factors have a much greater affect on accuracy than the shot-by-shot variations of the rilfe.

the L85, to name the example i am most familar with, if placed in a vice or braced in some smillar manner, will happily shoot with a spread of around an 25mm/1 inch or so at 100 meters. However, when shot by the average squaddie. the group size typically sits around 100mm, or 4 inches (when we bother to mesure group size). I'm sure that, for pretty much every assualt rilfe out thier, the bullet spread of the rifle is unlikey to factor into the users accuracy, in that it[s effect is swamped by other factors


In terms of game mechanics, what i mean is that the skill of the user with the weapon matters far more than the weapon itself, at least for 'line' infantry weapons and such. The difference between someone who has never fired a rifle and someone whos had a week or two of intensive training is considerable. however, it is very unlikey that a person can shoot well enough that he reaches the proformance limits of his rifle, to my knowledge.

[fusilier]

Greeks had lots of systems, I was fairly sure that what I described was essentially Aristotelian (though it's been some time since I was looking at that stuff, so I might have got it somewhat mixed up). Certainly they recognized the universal attractive force, generally referred to as "love" (in some respects, superficially similar to gravity, but extended to all manner of phenomena). "Telos" is indeed the purpose, but it's more along the lines of "what is the purpose of the sun?" "It's to provide light and heat for living beings", etc. From modern scientific perspective, that was one of the main failures of ancient philosophy, the interest in "why?" rather than "how?" (the "how?" was still studied by craftsmen and engineers).

It wouldn't surprise me if both are correct. I think they had a tendency to use many arguments to describe the same thing. Totally agree about the why/how issue. One of the things about Aristotle's "physics" was that it tied everything together, often one couldn't refute one part of it without having to overturn the rest.

[fusilier]

In microgravity, the recoil springs (or hydraulics) will kill problems with accuracy. The real problem is the backwards drift you pick up from firing. But that's actually a very small force; one bullet does not have the momentum to send a ~100 kg object (like a man in a space suit) flying backwards, on either end of the gun.

Part of the problem here is that we're not really make it clear when we are talking about personal weapons, or artillery. I agree that on an individual the recoil from firing a bullet won't be too much. For a large artillery piece . . .

The real problem is that Aristotelean "physics" was not the same kind of animal as what we call "physics" today. Aristotle wasn't really trying to explain the physical mechanisms of motion and the nature of matter. He was trying to explain "why stuff moves" in the philosophical sense. Not "how do rocks fall," but "why do rocks fall?" And "rocks love to be closer to the ground" is as good an explanation for the philosophical-why of falling rocks as anything else.

This can be a surprise to physicists trying to read Aristotle's book Physics.

Yes, he was a philosopher (they all were) and he only hit science in a kind of tangential way. I found that bits and pieces of Plato's "science" are scattered throughout a bunch of philosophical works -- they clearly didn't make the distinction between philosophy and science as we do now. The ancient greek philosophers didn't do anything that we could call an experiment, but they did observe phenomena . . . although not too closely. Aristotle was by no means mathematically rigorous, in fact attempting to express some of his physics in mathematics would probably have been rejected by him (and usually when you do see an "expression" representing some aspect of Aristotle's physics it's misleading).

Nevertheless, his ideas had a huge impact on what could be called "science" in the western world for millennia! He may have been wrong, but he was so convincingly wrong that it was not until people like Galileo that his ideas started to be seriously challenged. On the other hand, Galileo is probably the first "scientist" in the modern sense.

[fusilier]

speaking as a soldier, I can say that, in regards to the standards of shooting I am expected to meet, how you hold the firearm is much more important that what firearm you are holding. That is, vairation in body position, point of aim, and other 'human' factors have a much greater affect on accuracy than the shot-by-shot variations of the rilfe.

the L85, to name the example i am most familar with, if placed in a vice or braced in some smillar manner, will happily shoot with a spread of around an 25mm/1 inch or so at 100 meters. However, when shot by the average squaddie. the group size typically sits around 100mm, or 4 inches (when we bother to mesure group size). I'm sure that, for pretty much every assualt rilfe out thier, the bullet spread of the rifle is unlikey to factor into the users accuracy, in that it[s effect is swamped by other factors


In terms of game mechanics, what i mean is that the skill of the user with the weapon matters far more than the weapon itself, at least for 'line' infantry weapons and such. The difference between someone who has never fired a rifle and someone whos had a week or two of intensive training is considerable. however, it is very unlikey that a person can shoot well enough that he reaches the proformance limits of his rifle, to my knowledge.

I suppose if you are comparing the accuracy of different weapons, benchrest tests will probably give you some factor that you can quantize. But I think that Storm Bringer is basically right in that it's the skill of the user that will make the big difference. Other factors like how well laid out the sights are, and general ergonomics could also make a difference, but all of those are hard to quantize. One of the things that GURPS has is "familiarity penalties," which is a concept that I like. If you aren't used to firing a specific gun, you may find it difficult/awkward when you first pick it up.

[Norsesmithy]

I suppose if you are comparing the accuracy of different weapons, benchrest tests will probably give you some factor that you can quantize. But I think that Storm Bringer is basically right in that it's the skill of the user that will make the big difference. Other factors like how well laid out the sights are, and general ergonomics could also make a difference, but all of those are hard to quantize. One of the things that GURPS has is "familiarity penalties," which is a concept that I like. If you aren't used to firing a specific gun, you may find it difficult/awkward when you first pick it up.

I think that Storm Bringer's point is a very valid one, especially at controlled ranges. However, the rifle and cartridge (and bullet selection, IE 55 grain vs 69 grain etc) is going to have a great effect at targets at unknown ranges, or between two different weapons chambered in different cartridges.

To take the infamous AK as an example, a high quality (Russian, Bulgarian, Yugoslavian, or American manufactured) example can generally print 2-3 MOA groups at 100 meters (eg, 60-100mm), but, compared to the L85 or M16, its bullet travels at much lower velocity, so at longer ranges, the drop can mean that being 10 meters off in your range estimation can be the difference between hitting your target and hitting dirt. Seriously, 7,62x39 drops almost a meter between 300 and 400 meters (and its shooting nearly a meter low at 300).

When shooting at known ranges, I can hit dinnerplate sized steel gongs out to 150 meters with my handgun, but at 100 meters, I hold ~70cm high, and at 150 meters, its almost 160cm, so if it were an unknown distance, and I guessed the distance wrong, I'd be in a lot of trouble.

The rule of thumb I'd always heard was that when people are shooting back, you can expect your groups to be quadruple the size they are when you are shooting briskly at the range.

Despite that, after the Battle for Fallujah, the United Nations sent investigators to the city to determine whether or not the Marines had been executing people, because so many of the opposing force had been shot in the head.

[Mike_G]

Despite that, after the Battle for Fallujah, the United Nations sent investigators to the city to determine whether or not the Marines had been executing people, because so many of the opposing force had been shot in the head.

Oooh.

Rah.

[Norsesmithy]

I can't find the reference to make sure I am remembering this right, but back in like, '06, a Marine Corps General called the ACOG the greatest advancement in individual rifleman effectiveness since the (either brass cartridge or M1 Garand).

Apparently they are more durable than iron sights too, because the percentage of ACOGs that have to be looked at by an armorer is smaller than the percentage of detachable carry handles.

[Wind d8/d12]

I love ACOGS, they're a perfect accessory, the thick rubber guards protects against all but the most serious bumps, and even if they lose their zero after a big shock, they hold a point of aim without any parallax! And I wish I could smack around some people complaining about "Jesus Guns" Trijicon is a private supplier that doesn't receive government funding. They can put whatever they want on it.

In my D20M games an Acog increased range increment by X1.5 and added HP to the weapon (not hardness though) but I used a weapon degradation homebrew.

[fusilier]

I think that Storm Bringer's point is a very valid one, especially at controlled ranges. However, the rifle and cartridge (and bullet selection, IE 55 grain vs 69 grain etc) is going to have a great effect at targets at unknown ranges, or between two different weapons chambered in different cartridges.

To take the infamous AK as an example, a high quality (Russian, Bulgarian, Yugoslavian, or American manufactured) example can generally print 2-3 MOA groups at 100 meters (eg, 60-100mm), but, compared to the L85 or M16, its bullet travels at much lower velocity, so at longer ranges, the drop can mean that being 10 meters off in your range estimation can be the difference between hitting your target and hitting dirt. Seriously, 7,62x39 drops almost a meter between 300 and 400 meters (and its shooting nearly a meter low at 300).

When shooting at known ranges, I can hit dinnerplate sized steel gongs out to 150 meters with my handgun, but at 100 meters, I hold ~70cm high, and at 150 meters, its almost 160cm, so if it were an unknown distance, and I guessed the distance wrong, I'd be in a lot of trouble. [. . .]

This was the logic behind the 7.35mm M1938 Carcano rifle. Experience had shown that most rifle fire was being done at around 200 meters or less, with machine guns being used for longer ranges. So the M1938 has sights fixed at 200 meters: at 100 meters the bullet will be approximately 6 inches high. If the soldiers aim for the torso (and their aim is true), then they should get a hit out to around 220-230 meters.

A lot of head shots could also be the nature of the fighting. Hiding behind walls or poking out of windows, the head will be exposed while the rest of the body is protected. Helmets were (re)introduced in WW1 because trench warfare resulted in a large number of head injuries.

[Stephen_E]

Yes, I can see it been a bit hard to hit people anywhere but the head and arms because those are the bits they have to expose, and the hands, lower arms get partly shielded by the gun.

Stephen E

[Dervag]

P.S.: I'm not an US citizen and so cannot buy and download declassified Pentagon files (and I'm pretty sure I'm not allowed to have them, too).

I thought the whole point of declassification was that it is now safe for foreigners to look at the declassified information...

You could look for similar information on your own country.

Haven't thought of emailing the manufacturers - good idea, although I doubt the military ones will reply. Gun nuts tend to be rather . . . 'unstable'; if you know where I can find some of the more reliable ones, do tell.

You could seek out half a dozen of them and average out their wilder claims.

I worked on this very same issue some days ago. I have not kept any of my notes, but apparently the ranges in d20 modern seem to be quite accurate.

Due to air friction, a bullet slows down all the time it travels before it hits something and finally reaches terminal velocity, which is the same speed and energy it has when droped from a couple of meters height.

Nitpick: a few meters isn't enough to bring anything to terminal velocity, unless it's already deployed its own parachute...

Have you visited the Real-World Weapon or Armor Question thread? I found it hiding down on page 2.

Yeah. Now that it's been de-stickied, it's less visible; people who don't already know it's there are more likely to miss it.

Beyond that, I've heard (not actually studied myself) that most modern firearms are more accurate than their users, at least at close/moderate ranges. That is, a gun is going to fire at whatever you point it at, with the reasons for missing being bad aim, bad timing, or misaligned sights. I would assume that extreme sniper range would be more affected by gravity and winds, although I would take that range to be measured in miles.

The record is something over 2000 meters, though that's generally only possible for very good marksmen firing high-velocity rifles (typically chambered in .50 BMG).

Part of the problem here is that we're not really make it clear when we are talking about personal weapons, or artillery. I agree that on an individual the recoil from firing a bullet won't be too much. For a large artillery piece . . .

A large artillery piece in space will be braced to a large platform, which moves less in response to a given recoil. Also, the large platform will typically have engines, which can be used to cancel out the recoil over time.

Nevertheless, his ideas had a huge impact on what could be called "science" in the western world for millennia! He may have been wrong, but he was so convincingly wrong that it was not until people like Galileo that his ideas started to be seriously challenged. On the other hand, Galileo is probably the first "scientist" in the modern sense.

Me, I disagree, I say Archimedes, but I'm weird that way.

Also, Galileo was very much part of the scholar-tradition of his era. He had many of the bad habits of the medieval scholar: treating his results as proprietary rather than publicizing them, being strongly influenced by political patronage, dabbling in philosophical and theological implications of his work (which is part of how he got in trouble with the Church)...

If we talk about science as a practice, we really need to look at the generation after Galileo to see that intellectual tradition start to emerge in northwestern Europe.

[fusilier]

A large artillery piece in space will be braced to a large platform, which moves less in response to a given recoil. Also, the large platform will typically have engines, which can be used to cancel out the recoil over time.

Exactly. Which is why I said it would need a lot of mass, and not some kind of recoil buffer.

Me, I disagree, I say Archimedes, but I'm weird that way.

Also, Galileo was very much part of the scholar-tradition of his era. He had many of the bad habits of the medieval scholar: treating his results as proprietary rather than publicizing them, being strongly influenced by political patronage, dabbling in philosophical and theological implications of his work (which is part of how he got in trouble with the Church)...

If we talk about science as a practice, we really need to look at the generation after Galileo to see that intellectual tradition start to emerge in northwestern Europe.

I'll admit that I'm not that familiar with Archimedes, although I would give him credit in that he was a first rate mathematician and he applied math to practical problems.

I disagree about Galileo. Yes, he was definitely part of the patronage system, and this did require keeping some things secret, or obfuscating his techniques, so it wasn't too easy to replicate. A consequence of the patronage system, he needed to be able to convince those in power of his discoveries, but at the same time prevent other "philosophers" from copying his results, and maybe discovering something new. This was mainly, however, applied to technology, and not to science. And that's where Galileo differs from his predecessors. He applied mathematics to natural phenomena (like things falling), and conducted detailed experiments to validate theories. He had to take on religion, because the church, which had widely accepted Aristotle, attacked his discoveries. If he made his discoveries known, he would have to deal with the church. There was no way around that issue. He also popularized science in a way that had never been done before. His dialogues were designed so that any educated person (in Italy, originally) could read them, and not just philosophers. To be sure, he would cast the occasional horoscope when asked; that was part of his job as an astronomer, but there's little evidence that he actually believed in it (unlike Kepler). He's probably more responsible for launching modern science than anybody else, if it's fair to point to a single person.

[Stephen_E]

Nitpick: a few meters isn't enough to bring anything to terminal velocity, unless it's already deployed its own parachute...

I'm pretty sure a few metres is enough for a mouse to reach terminal velocity.
Not sure about a bullet, but suspect terminal velocity is pretty low on a bullet. Without spin they aren't particuly aerodynamic, and are pretty light.

Me, I disagree, I say Archimedes, but I'm weird that way.

I'll go with you on that.
Hell, I'd put Leonardo before Galileo. He didn't just invent contraptions, he worked out the principles for those inventions to operate.

None of them had a scientific community to be part of, although the stirings of scientfic comunities were starting during Galileos time.
And really it's the concept of a scientific community that's important, rather than any 1 scientist, no matter how brilliant (and both Archimedes and Leonardo had brilliance in spades, moreso than Galileo).

Stephen E

[Mike_G]

A lot of head shots could also be the nature of the fighting. Hiding behind walls or poking out of windows, the head will be exposed while the rest of the body is protected. Helmets were (re)introduced in WW1 because trench warfare resulted in a large number of head injuries.

Kinda.

If you are firing out a window, most modern rifles will put a round through the wall you're hiding behind with little trouble. It's easier to aim a few inches below the sill at where center mass has to be than hit a head shot.


Buildings really aren't the protection people think they are.

A trench will protect you, sandbags or a decent berm will, but wood, brick or cinder block really doesn't do a very good job.

Helmets were designed to prevent shrapnel injuries, and fragments dropping into a trench. Most will not stop a rifle or machine gun bullet. They were a reaction to shelling, not sniping.

The nice thing about head shots is they make the guy fall down now. That's why you take one. Put a hole in a guy's torso and he will bleed out, but he may empty his magazine at you first.