order of firing from guns

ShuRugal · November 29, 2015

Some guns do and some do not....

At least that was my experience.

Just like some bikes use some oil and some do not! :)

In my experience, some bikes leak oil because they have seen incomplete maintenance.

In my experience so far in the Army (I can only boast 3 years, so the Appeal to Authority argument would kinda fall flat) any piece of equipment that has been around long enough has exponentially increasing odds of encountering an owner who doesn't give a shit and lets "minor" maintenance procedures fall by the wayside.

I can definitely believe that the Army has a non-negligible number of M2s with headspace problems, because I know for a fact that the army has a non-negligible problem with equipment owners who don't give two shits. However, this is not a flaw of the weapon itself. It doesn't even necessarily reflect poorly on the current equipment owner/maintainer; just means that someone, at some point, allowed their weapon to be used while it was NFMC, and the wear/damage caused now means that weapon is no longer reliable.

None of this means that headspacing problems should be introduced to the sim, unless you are proposing a DCS: Armorer module.

Crumpp · November 29, 2015

Maintenance is already modeled in the fact your airplane and weapons work like they should.

It is up to you to operate them as you should and resistance to that concept came about when the burst limits where posted.

Burst limits should be modeled in all automatic weapons and I would propose that. It is just the engineering reality.

ShuRugal · November 29, 2015

Maintenance is already modeled in the fact your airplane and weapons work like they should.

It is up to you to operate them as you should and resistance to that concept came about when the burst limits where posted.

Burst limits should be modeled in all automatic weapons and I would propose that. It is just the engineering reality.

that could be interesting. decreasing accuracy until repair/respawn if overburst?

Crumpp · November 29, 2015

that could be interesting. decreasing accuracy until repair/respawn if overburst?

Exactly.

Push it and you will get malfunctions!

Some aircraft in World War II even had systems that could cycle the weapons actions to clear malfunctions.

Obviously it was an issue and should be a part of the experience! :smilewink:

ShuRugal · November 29, 2015

Exactly.

Push it and you will get malfunctions!

Some aircraft in World War II even had systems that could cycle the weapons actions to clear malfunctions.

Obviously it was an issue and should be a part of the experience! :smilewink:

Not sure I would call loss of accuracy a malfunction... I can't apply SPORTS to fix my shot group, after all ;)

OutOnTheOP · November 29, 2015

that could be interesting. decreasing accuracy until repair/respawn if overburst?

Not how it works. While overheating a barrel does decrease accuracy, that's only even noticeable in the context of a match-grade rifle. As in, my groups will open up from between a half and one minute-of-angle to perhaps 2 minutes of angle if I run a rifle REALLY hot. The reason for the ever-so-slight change in accuracy is the rate of expansion of the metal parts of the rifle are different, so the tension between parts changes.

Still, that's the difference between hitting a golf ball at 300 yards, and hitting a softball at 300 yards. With a heavy machine gun, rattled around by recoil, inherently designed with a barrel that is *not* permanently/firmly mated to the receiver, mounted on a not-perfectly-rigid mount, in a not-perfectly-rigid wing, you would never, EVER notice the difference in group size between a hot and cold barrel. The group is already something around 15 or so minutes of angle (roughly 4 mils) to start with, which means each gun covers a 5 foot area at 400 meters. The game currently appears to model the hot guns' groups opening up to a nigh-ludicrous ~90 minutes of angle dispersion, with rounds passing either side of the target's wingtips at 1000 feet!

Now, if you hold the trigger down for the full 300 to 500 round belt, you MIGHT burn the rifling out of the barrel, and then, yes, you would lose accuracy. Moreover, you would lose it permanently (at least, until the barrel was replaced), and not just until the barrel cools.

But barrel heating has, in reality, a negligible effect on mounted machine guns. Most shooters never even notice it with scoped rifles, because the effect of their own inherent errors in aiming are far greater than that of barrel heat.

In fact, in my experience, ammunition type has much more bearing on accuracy than does barrel heating.

But the notion that firing a gun hot will cause it to jam is ludicrous, and the idea that accuracy goes completely pants if you fire more than a 20 round burst is equally bunkum. And even a twenty-round burst is a long, almost two-full-second affair. The only time jamming due to heat becomes an issue is when you get parts SO HOT they start to materially fail. As in, when you start to soften metal. Takes more than a few hundred rounds for that.

Edited November 29, 2015 by OutOnTheOP

OutOnTheOP · November 29, 2015

Ima just leave this here:

[ame]

[/ame]

And, as a privately-owned class III firearm, THAT M2 is AT LEAST 40 years old, and probably has many, MANY thousands of rounds through it already. Yet, 100 rounds straight, no jam. Barrel's not even particularly hot, just a little smoke because the oil is past its smoke point.

And again:

[ame]https://www.youtube.com/watch?v=tFwKWLQBNJM[/ame]

Funny, gun didn't just seize up. Barrel's not glowing or nothing. 10-15 second straight burst, and gun runs just fine. Not even smoke this time. Listen to how LONG that burst takes to complete. Think you're ever going to hold the trigger that long in a fighter?

Somewhere out there is a video of some guys at a machine gun shoot with an M60 that they ran for something like 1000, 2000 rounds STRAIGHT BURST. Barrel got so hot it glowed and sagged. But you know what? The gun still cycled and fired.

Edit: for your enjoyment, here it is:

[ame]

[/ame]

Heat doesn't jam guns. Guns jam, but heat is almost never the reason.

And it's not just M2s, other guns can also fire ridiculous bursts without seizing. Mind you, the M2 is recoil-operated, and has ZERO moving parts in the barrel, so you don't have to worry about frying your gas regulator, boring out your gas port, or destroying your piston, operating rod, or other pieces prone to breaking in other machine gun designs. All the heat in the M2 is contained in the barrel, which has ZERO moving parts. Not like the M60 above, or this M249, which both have much thinner profile barrels, and a gas regulator/ piston design up there where all the hot gas is:

[ame]

[/ame] Edited November 29, 2015 by OutOnTheOP

OutOnTheOP · November 29, 2015

I know, I know, some of you are probably stuttering "but, but, FM 3-22.68 on table 5-2, page 5-9, clearly states that the rapid rate of fire for the M60 is only 200 rounds per minute, in burst of 6-8, with 2-3 second pauses between bursts! Clearly, despite documented evidence to the contrary, long bursts are impossible!"

Whatever. Even FM 3-22.68, 21 July 2006, clearly states that in an emergency, the gunner can use cyclic rate for one minute on a 60 or 240 with an uninterrupted ammunition supply. That's 550-950 rounds straight, by the way. There is nothing that makes the 60 or 240 special, that they would be able to do that (fire a long, long burst at the expense of wearing out the rifling), where an M2 couldn't. Exactly the opposite, in fact. The M2 is temperature-insensitive: it has no moving parts whatsoever in the barrel and chamber area, where the heat is. There is every reason to assess that the M2 is LESS prone to barrel heating-induced failures than gas-operated systems like the M60 and M240.

These limits listed in the manuals are NOT because the gun will stop working if exceeded. They are there to reduce wear and tear on the barrel, to maintain a sustainable ammo expenditure rate, and other factors. They are NOT accurate representations of mean rounds between failure on cyclic rate.

Edited November 29, 2015 by OutOnTheOP

Echo38 · November 30, 2015

In my personal (limited) experience shooting fully-automatic weapons, heat was only ever an issue for burning one's hand! All of the jams I've experienced (and I experienced more than my share) were due to either cheap ammunition being used, or the weapon being improperly maintained. I know this because most of my jams occurred when firing cheap ammunition in my semi-automatic weapons; I had very few jams when firing good-quality ammo through full-auto guns.

When I said, earlier, that realistic jams were currently not modelled in DCS, I was not implying that they should jam due to overheating. The specific cause of jamming I had in mind, actually, was jamming due to firing under high G-loads (cannons and machine guns alike). That's the problem I've heard the most about, with Second World War fighters.

Edited November 30, 2015 by Echo38

Crumpp · November 30, 2015

https://books.google.com/books?id=nOVGjqUavScC&pg=SA2-PA12&lpg=SA2-PA12&dq=Machine+Gun+malfunction+overheat&source=bl&ots=sZm50YTsbz&sig=UkIkIUch3A3Vk6vRGCZ6Cc5ML4o&hl=en&sa=X&ved=0ahUKEwionIPP-bbJAhVHTSYKHVwmD8E4ChDoAQgsMAM#v=onepage&q&f=false

[Knight] · November 30, 2015

In my personal (limited) experience shooting fully-automatic weapons, heat was only ever an issue for burning one's hand! All of the jams I've experienced (and I experienced more than my share) were due to either cheap ammunition being used, or the weapon being improperly maintained. I know this because most of my jams occurred when firing cheap ammunition in my semi-automatic weapons; I had very few jams when firing good-quality ammo through full-auto guns.

When I said, earlier, that realistic jams were currently not modelled in DCS, I was not implying that they should jam due to overheating. The specific cause of jamming I had in mind, actually, was jamming due to firing under high G-loads (cannons and machine guns alike). That's the problem I've heard the most about, with Second World War fighters.

Our M2 jammed every 3-5 rounds in afghan and got to the point we had just stop trying and I personally would pop out of the turret with my m16 to return fire. And the M2 also starts slow gets faster than slows down again in rate of fire but situation dictates and the use of clp was applied, so that could have gunked it up a bit. Correct me if im wrong but didn't the P-51 use a different variation of the m2 for air use because they produce a higher fire rate and our more reliable than the ground versions.

OutOnTheOP · November 30, 2015

;2573366']Our M2 jammed every 3-5 rounds in afghan and got to the point we had just stop trying and I personally would pop out of the turret with my m16 to return fire. And the M2 also starts slow gets faster than slows down again in rate of fire but situation dictates and the use of clp was applied' date=' so that could have gunked it up a bit. Correct me if im wrong but didn't the P-51 use a different variation of the m2 for air use because they produce a higher fire rate and our more reliable than the ground versions.[/quote']

Sounds like either your headspace and timing was set improperly, or you had a worn action spring. ...or just a bunch of dust and grit mixed in with your CLP in the receiver. At any rate, it wasn't excessive heat that does that. From your description of starting slow, getting faster, then slowing down, I would guess your problem was fouling: as it cycled, it blew the accumulated dust and grit out, then filled with powder residue and other crap as you fired more. Probably a result of over-lubricating the weapon. Too much CLP will tend to accumulate sand and dust; in the desert it's best to start with a nearly-dry gun; pour in some CLP as needed. How many rounds did you go through in the engagement you're describing?

Yes, the airborne M2 used a much lighter barrel; this allowed the action to reciprocate faster, because it is recoil driven, and the less inertia the recoil has to fight, the faster it recoils (and therefore the faster it cycles).

OutOnTheOP · November 30, 2015

When I said, earlier, that realistic jams were currently not modelled in DCS, I was not implying that they should jam due to overheating. The specific cause of jamming I had in mind, actually, was jamming due to firing under high G-loads (cannons and machine guns alike). That's the problem I've heard the most about, with Second World War fighters.

Which is a perfectly reasonable stance, and one I generally agree with. Moreover, they fit well in game design, because firing under g load is something that can be deliberately avoided, and which is an easily identifiable cause-effect event that players can make an informed decision to risk, or play safe. I would note, however, that the M2 was (compared to other airborne weapons of WW2) fairly reliable under g load... at least when mounted upright, as in the P-51D. There was some difficulty with the M2 jamming under g load in earlier P-51 models, but that was due to the guns being mounted tilted sideways to fit into a thinner wing section, which forced the feedway to go through a fairly sharp bend right before the belt entered the receiver. This was rectified in the P-51D.

However, the bulk of this conversation has been regarding the M2's alleged propensity to jam due to "wandering" headspace and timing, and then, when that was disproven, about jamming (or inaccuracy) due to excessive heating (which, incidentally, should be a greater issue to the FW190 and Me109, whose guns are mounted in the engine bay and run hotter than wing guns on account of engine bay heat).

Anyhow, heat jams and headspace/timing jams are the false assertions to which I am responding.

Crumpp · November 30, 2015

;2573366']Our M2 jammed every 3-5 rounds in afghan and got to the point we had just stop trying and I personally would pop out of the turret with my m16 to return fire. And the M2 also starts slow gets faster than slows down again in rate of fire but situation dictates and the use of clp was applied' date=' so that could have gunked it up a bit. [b']Correct me if im wrong but didn't the P-51 use a different variation of the m2 for air use because they produce a higher fire rate and our more reliable than the ground versions.[/b]

Headspace...weird huh?

The M2 Aerial Weapon was lighter which caused the increase in ROF. That is also why it has slightly more restrictive burst limits over its heavier barreled ground based cousin.

At any rate, it wasn't excessive heat that does that.

Excessive heat causes expansion.... (basic physics)

Which causes friction....(basic physics)

Which causes malfunctions.....(as the Browning engineers say)

:thumbup:

You wonder why the folks on the youtube videos thought it was "neat" and exceptional enough to record when firing those long burst? Not to say a fresh gun would have any problems for the first burst or two. In fact, 150 round single burst is the cook off limit for the lighter barrel aerial weapon. I would expect the heavier barrel of the ground variant to withstand a little more but even then you are risking it.

It is still abuse of the weapon and not how it was designed to be employed. Like any tool, use it in a way it was not designed for at your own risk.

Trust me, it is a bad feeling when your machine gun goes down when you really need it. People get excited real fast.

This is a game. What are we trying simulate? How the equipment works and was employed or possibility?

It would be possible to run around with your weapon on full auto jumping like a rabbit in the Xbox games my kids play in a real firefight.

However, there are good physical reasons why real urban combat does not consist of jumping around with your weapon spraying on full auto....

OutOnTheOP · November 30, 2015

Words

Seriously, dude. Stop trying to mansplain in your overbearing, smarter-than-thou manner. I have plenty of time in the service. I have plenty of time on the M2. More than a few firefights, thank you very much.

I am also a gunsmith. And conversant in basic physics. Do you REALLY think that a hundred or so degrees Celcius of barrel heat makes a lick of difference in the tolerances of the functioning parts of the M2? By the by, the coefficient of thermal expansion of steel is, depending on the alloy, 0.000005 to 0.000009 inches per inch thickness per degree F. Let's go with a middle-of the road number of 0.00000645 inches per inch per degree F. The barrel walls of the M2 are about an inch thick at the chamber (slightly under, really), and will expand both out (away from the chamber) and in (toward the chamber). So the reduction of chamber size, if you heated the barrel TWO HUNDRED DEGREES F, would be all of 1.29 THOUSANDTHS OF AN INCH.

There is more than enough clearance between the barrel extension threading and the barrel threads that this will not seize... and even if it did, so what? That part isn't *SUPPOSED* to move while the gun is in operation.

So the only part that heat *might* induce jams, is in the chamber itself. Only... the chamber is quite generously cut, as is the case in pretty much every machine gun chamber ever, and the cartridge is tapered for ease of chambering. There is plenty of tolerance there for the couple thousandths of an inch that it might expand. Powder fouling will be responsible for an order of magnitude more dimensional shrinkage of the chamber than will thermal expansion. And, oh by the by, Browning kind of, you know, *made allowance* for powder fouling and the other assorted detritus that might make its way into the chamber. :doh:

Never mind that there's about 80 pounds of spring pressure and a ton of inertia behind the bolt assembly, so even IF the chamber managed to magically shrink due to thermal expansion, the bolt would actually swage the cartridge in *anyway*. I can tell you've never hand-loaded cartridges of any type; it is remarkably easy to re-size a brass cartridge case a couple thou.

Technical jargon-tossing aside, you're really flailing at your argument here.

Edited November 30, 2015 by OutOnTheOP