Are machineguns in general purposely made inaccurate?

Carlos Hathcock made a 2,000 yard shot with an eight power Unertl scope mounted on a std M2 Browning.

I don't think it is the machine gun that is inaccurate but the way it is used.

Gunnery Sergeant Carlos Norman Hathcock II, "On some occasions, however, he used a different weapon: the .50-caliber M2 Browning Machine Gun, on which he mounted the Unertl scope. This weapon was accurate to 2500 yards when fired one round at a time. At one point, he took careful aim at a courier carrying a load of assault rifles and ammunition on a bicycle. He had second thoughts when he saw a 12-year-old boy in his sights, but after considering the intended use of those weapons, he fired, hitting the bicycle frame. The boy tumbled over the handlebars and grabbed a gun, so Hathcock killed him." (Source Marine Sniper, Chapter 1.)

.308

I am not an Emma Gee but I figure most of the cone of dispersion is due to vibration in firing. I have read that FN USA uses M240 barrel blanks for their M70 based sniper rifles, so the barrels are not intentionally made sloppy.

Peter J. Kokalis said in SoF that the flaw in the M239 was that its natural dispersion was vertical which makes overhead fire risky instead of horizontal which covers more beaten ground.

the .50-caliber M2 Browning Machine Gun, on which he mounted the Unertl scope.

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We had the same set-up at 5th. Army AMU Sniper School in 1968-69-70.
It was too easy to hit silhouette targets at 1,000 yards!

Any "cone-of-fire" is caused more by the GI ammo specs then any planned inaccuracy of the gun itself.
Most GI Ball & AP ammo is not capable of MOA accuracy, especially when you mix tracers in with it in a MG belt.

And you have a certain amount of slack in the best of tri-pods and other gun mounts that allow a certain amount of movement.

You also may have varying wind drift of the individual bullets in a sting at long range.

The only machinegun I know for certain had a designed-in cone of fire was the Gattling Gun.
They spread shots horizontally as you happly cranked away. The elevation setting is very positive, but the windage adjustment on the carrage allows the muzzles to sweep sideways slightly as you cranked.



Like this!


rcmodel

Any "cone-of-fire" is caused more by the GI ammo specs then any planned inaccuracy of the gun itself. Most GI ammo is not capable of MOA accuracy, especially when you mix tracers in with it

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Mix tracers in with regular ball and shoot it at 1000 yds (1 tracer to 4 ball is typical for machinegun belts) and the tracers will all hit significantly lower than the ball as the phosphorus burns and makes the bullet lighter. (which is very important to realize when night firing at extended ranges)Also our 7.62 nato rds experience tracer burnout around 700 yds.

A qualified machinegunner will tell you about the Cone of Fire and the Beaten Zone.

In full-automatic fire from a machinegun, each bullet will take slightly different trajectories due to vibration, the gunmount, variances in ammunition, recoil, etc - this is the Cone of Fire. The area where all those bullets strike the ground is called the Beaten Zone - which varies according to the terrain eg. rising terrain will have a shorter Beaten Zone, but dropping terrain will have a longer Beaten Zone.

The width of the Beaten Zone varies with distance, but 2 yards wide would be normal at typical MG ranges.

Carlos Hathcock made a 2,000 yard shot with an eight power Unertl scope mounted on a std M2 Browning

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close enough! recorded distance was: 2,286 meters or 1.42 miles

machine guns are standardly used more for supression rather than point targets, taking out a larger crowd vice a single person. theyre perfect on when going against a light armored vehicle or when you are trying to lay down cover fire to get your buddies across the street. accuracy is left to the rifleman taking the precise well aimed shot while the machine gun provides cover. thats our end of the spectrum. they are not purposely made to be inaccurate, just mass produced to fufill the role we need them for. the M2 when fired in single shot is a terrible threat to who is on the other side, but once you lock the bolt release down and its components start rattling around (to include the gunner) then thats a different story. speaking of which, the shooter, as always, determines where that round will most likely strike, and with repeated recoil and the bolt slapping around, usually the only shot that hits target is the first one.

Got to love the Ma deuce! God bless Carlos Hathcock!

We always counted on the secondary projectiles to create more damage than the individual projectiles. We shot in front of advancing targets purposely to throw up rocks and ricochets into their line.

Want to aim at a particular target, use a rifle, not a machine gun.

(My experience is with the M60)

The longest shot I ever made on anything was with a single round from an M240B belt at 1,000 yards.

Yes, I meant to do it.
(But that doesn't mean I wasn't lucky as hell to actually make a hit!)

Not exactly scientific, but in my mind it does sort of detract from the idea that a MG would be made innaccurate on purpose.

Machine gun ammunition tends to have looser tolerances than rifle ammunition to produce greater dispersion as well. I can't recall if this is true with M855 5.56mm, but is the case with M80 ball 7.62mm.

I'm with HorseSoldier, I was trained that the MG was inherently accurate, but the ball ammo we were firing was as little squirrelly intentionally to open things up a bit.

Hell, your elevation adjustments on the M2HB are something like a minimum of 1 mil, or 3.438 MOA. At 2000 yards that would mean his minimum vertical adjustment distance would be 70 inches or so. When you consider that the platform is only about 1-2 MOA at best, with normal belted API/APIT probably giving you 2-4 MOA...I just can't see how a hit at 2000+ would be anything other than sheer, unadulterated blind luck. Let alone even seeing a target at that distance with an 8-power scope.

Hathcock made a cold bore shot with the M2. Firing it full auto will heat the barrel enough to make it "loosey goosey" and somewhat less than a MOA gun.

Methinks that quick-change barrels might have a bit to do with it as well.


Thanks for the great pictures rcmodel!

Disclaimer: I am not an expert at all, just sort of thinking out loud...
Seems to me that recoil, vibration/flex and the barrel rapidly heating up would have as much if not more to do with accuracy than anything else. With that in mind, the designer's time would be better spent making it more reliable under stress than worrying about moa accuracy.

Machine gun ammunition tends to have looser tolerances than rifle ammunition to produce greater dispersion as well. I can't recall if this is true with M855 5.56mm, but is the case with M80 ball 7.62mm.

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I wasn't aware that there was any difference between rifle ammo and machine gun ammo.

Standard 7.62 ball is M80:
http://www.globalsecurity.org/military/systems/munitions/762.htm

Standard 5.56 ball is M855 (was M193 until the M249 and M16A2 came out):
http://www.globalsecurity.org/military/systems/munitions/556.htm

If machine gun and rifle ammo had different specifications, wouldn't they have different model numbers?

The Bren gun was purposely engineered to loosen up the cone of fire to give a better beaten zone, by allowing the recoil spring guide rod to "float" a little bit from shot to shot, but I can't recall any newer designs having this done; this is also as good a place as any to show a 50 M2 being used for long-range "sniping", during the Korean War:

The early BARs were too accurate so they mounted the bipod on the flashhider to move the bbl around, with the intent of messing up its pinpoint accuracy.

The Bren's 7.62, the L4 variant was and remains quite ridiculously accurate for a (not particularly light) LMG.

This is partly due to the higher tolerances when retrofitted from .303 as well as the lower rate of fire/30 round mag that tended to keep the whole unit relatively cool in use.

I saw consistent 800 mtr 6" groups from experienced gunners when shot single shot.

as an ex sf sustained role machine gunner
in the light role a fn mag gpmg has a very small beaten zone mostly because you should'nt be firing very long burst from it
mount on a tripod and you get a pronounced danger zone can't remember the details but something like 100 metres long 5 metres wide firing a burst of 50 rounds anybody in that zone will get hit at least once.
could hit out to two k using iron sights
with a gps and map predicted fire could hit targets out to 4k

with a gps and map predicted fire could hit targets out to 4k

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Does the US still do indirect machinegun fire? I only occasionally read about it in WWII.