You know in the movies, where people get hold of powerful automatic weapons - rifles or machine guns - and fire them on full automatic for ages? US troops in training carry out a barrel change on an M240B machine gun. Credit: Sgt Lindsey Bradford/US Army Goddammit Kowalski, it's supposed to come off in your hand That's quite …
RE: Your missing several other problem
Room entries, assaulting enemy positions at close quarters, suppressive fire upon initial enemy contact. There are plenty of reasons to fire more than 3 rounds in a burst, and us English with the L85A2 trust our soldiers to choose when to use each fire mode, rather than restricting them to burst fire. Plus the article was mostly referring to LMGs, which as you mentioned doesn't suffer from these unsupported firing position problems.
Also they claim to have fired the weapon at 1100 degrees, so assuming this was done using a hand portable prototype, I assume they've overcome any other heat build up issues in the breach.
I don't really see what point you're trying to prove here, beyond bigging up your soldier knowhow. Which by the way really doesn't prove you know what you're talking about. I can take apart and put together a PC, but I don't know how everything works in it, and certainly couldn't claim expert knowledge on something like the PCI-E bus.
RE: Your missing several other problems
Yep it was fired from an "ARDEC Advanced Remote/Robotic Armament System" - standard small arms mounted on a remote firing system. So it can fire at 1100 degrees...
look here foot slogger. Some people have these things called ve-hi-cles. They have MGs on them too, oh and coax guns. And stacks of ammo in boxes.
M16A4 dont have fully auto because the yanks cant shoot for shit therefore cant be trusted with fully auto.
I think the cobalt barrels ARE intended for suppression weapons i.e. MGs rather than AWs
@ Anonymous Coward
"There are plenty of reasons to fire more than 3 rounds in a burst, and us English with the L85A2 trust our soldiers to choose when to use each fire mode, rather than restricting them to burst fire."
Actually no they don't. I AM a soldier in the British Army and automatic mode on the L85 is restricted in use unless your in very specific scenarios and even then you are trained to keep your bursts to approximately 3 rounds or less to prevent recoil climb. The M16A4 was an example I gave because that specific generation model appeared long after the L85 was designed and thus incorporated more enlightened thinking and also offers a way to limit the recoil. The original M16 had full auto too. I absolutely promise you by the time you have fired about 6 rounds from the L85 your rifle is pointing a good deal higher than where you aimed and will only continue to climb.
"Also they claim to have fired the weapon at 1100 degrees, so assuming this was done using a hand portable prototype, I assume they've overcome any other heat build up issues in the breach."
That's all fine and well if they have machined a NEW weapon or re-engineered an existing weapon for the barrel. However it's not a case of simply fitting the new barrels to existing weapons as the machining tolerances are not designed for constant fire. Plus I absolutely guarantee you put a round into the breach at 1100 degrees and it WILL cook off (Regardless of whether or not it's an open or closed bolt weapon). And with the current SDSR in place, I highly doubt we will be swapping our weapons out anytime soon.
All this is aside from the fact that automatic fire in an individual weapon is rarely used because apart from being up and close and personal, it's not effective. Single aimed shots are better. As for support weapons, well in a real contact you would simply never get the opportunity to fire at the weapons full cyclic rate. Ever. Even if the weapon is mounted or bipod based.
I'm not saying they are a bad thing, not having to carry and swap out a second barrel would be a great thing (And I speak from the heart having been an LMG gunner in Afghanistan) but there is no way that they would lead to any military switching its training or operating policy to one where you can blaze away (Or "hosepipe" as we refer to it. Imagine the rounds from the barrel as a stream of water from a hose).
ref: Your missing several other problems
"This is why a number of weapons such as the M16A4 and so on do not have a fully automatic mode. They have a three round burst capability as it's generally these three rounds that do anything."
On an SA80, this feature is controlled by the mechanical reliability of the weapon, magazine, and Radway Green supplied ammuntion.
"M16A4 dont have fully auto because the yanks cant shoot for shit therefore cant be trusted with fully auto."
Now why would you need any full auto when the mantra is 'one shot, one kill?'
"there is no way that they would lead to any military switching its training or operating policy to one where you can blaze away (Or "hosepipe" as we refer to it. Imagine the rounds from the barrel as a stream of water from a hose)"
However, that ability would be very desirable for remote controlled or autonomous turrets and I can easily imagine people in Pentagon salivating at the thought of sticking Aliens2-style turrets all around the perimeter of Kandahar Air Base (or along the Mexican border) and let them blaze away at anything that moves...
Why not bring back the vickers .303?
Ok, so it's not the most portable, but as a machine gun it's pretty good :-)
'The weapon had a reputation for great solidity and reliability. Ian V. Hogg, in Weapons & War Machines, describes an action that took place in August, 1916, during which the British Army's 100th Company of the Machine Gun Corps fired their ten Vickers guns continuously for twelve hours. They fired a million rounds between them, using 100 new barrels, without a single breakdown. "It was this absolute foolproof reliability which endeared the Vickers to every British soldier who ever fired one."'
If you need a machine gun get a good one - stop faffing around with wannabees.
The infamous test to destruction of a Vickers machine gun when they were going out of service and people wanted to know just HOW long they would have kept going for.
Someone who was a witness to part of it told me 7 days + 7 nights, and a LOT of trucks carrying crates of ammo in, and taking away the mountain of copper that was accumulating. You don't want to know how much ammo it used, cos we paid for it. Still, on the bright side a lot of it was war stocks that had to be disposed of anyway, but...
what's the mandrel made out of?
If your barrel is radiating high IR, you're a definite target for IR-seeking thingy-bobs...
@ Possible Problem
opposed to muzzle flash, body, or vehicle heat?
As this is the US military i'm guessing that the scaling is in Fahrenheit.
1100degF is going to stick out more than 96degF
Simples... errr... die shrink it and add more cores...
(There you go, that's the IT angle of the story)
1100 degrees of what?
1100 degrees of what Lewis? I'm assuming you are working with either Fahrenheit or Celsius, but it is unclear and makes a huge difference. I'm assuming that since you lifted most of the tech stuff straight from the linked article which was written by septics it must be Fahrenheit? Also the melting point of pure cobalt is only just below 1500 degrees Celsius, so presumably if the barrel got to 1100 degrees Celsius you would already be in the plastic flow region...
its a cobalt alloy, not pure.
Beware the cook-off!
Heat build-up can lead to rounds "cooking off", or firing unexpectedly when the gunpowder ignites due to heat. This can make the other members of your squad very unhappy when you're behind them covering their advance...
It may save the gunner from RSS as he won't need to hold the trigger pressed all the time...
Old problem, with an old solution
This is why most machine guns fire with an open bolt. That is, a round is not fed into the breech until the trigger is pulled, which releases the bolt, allowing it to close. This can be a little less accurate, because of the delay before the cartridge is fired, and the movement of the bolt mass.
Is approximately 366.666666667 soul bands.
how hot can the rounds get
just a thought
I'm not certain I'd be happy loading a round into a white hot barrel,
how hot can rounds get before they self explode ?
True, but open bolt setups such as the M60 and many other LMGs are immune to cookoff, which coincidently are the types of weapons these barrels are targeted at.
Made me think if a steel machine gun barrel can easily melt then it wouldn't be a problem for jet fuel to melt / weaken the steel columns in the World Trade Centre (so much for all the inside job using thermite / explosives on 9/11)
This process sounds Very similar to hammer forging (invented in 1939). That's where the barrel is drilled and honed, a mandrel is put in the center, and rotating auto hammers pound on the outside until the bore takes the rifling shape.
Anyway, this is a nice advance. From experience, I know barrels heat up Quick. This really doesn't fix that, it just allows you to get the barrel screaming hot without it failing. Of course, the weapon will have to fire from an open bolt, lest the heat alone fires the next cartridge - whether you mean too or not.
Flame, because this is hot stuff!
So when they shout FIRE!
they will be refering to the combustable aspects of the bush next to the 1100c barrel?
Ignoring the melting barrel bit, how well does the rifling last with this setup?
whilist you dont want an MG that is too accurate, converting it to an automatic musket would not be good either
Surprised this has not bee tried a *long* time ago.
Flow forming is a popular way to turn mostly cylindrical things with complex profiles (especially stuff that has walls that thicken in bands or taper from one end to another) often as parts of various bits of military hardware.
The smooth force applied suggests it would give a smooth internal finish as opposed to something made by many separate hammer blows.
AFAIK the technique works very well at well above room temperature, so the metal would be softer to begin with.
Gun barrels (certainly of the .50cal variety) are *well* within the range of objects made currently with this method.
The obvious joker is if is worked hot (or even warm) unless the mandrel is withdrawn *very* quickly the barrel cools and shrink fits onto the mandrel.
In principle a clever way to make a lot of something very difficult at a reasonable price.
unless the mandrel contracts at an equal or greater rate as it cools...
that is all.
and the best part is...
Each barrel will now cost a number of times more than current barrels.
So it is basically, apart from the cobalt alloy stuff, pretty much a standard hammer forged barrel.
Not exactly a new technique
BSA have been making gun barrels that way for decades - but they are a UK company so the septics, not knowing where abroad is and not trusting anything not invented in the US, wouldn't know that ...
That's mandrel, not mandrill http://en.wikipedia.org/wiki/Mandrill
"the US Navy (interested in equipping its marines and SEAL frogman-commandos better)"
While the civilian leadership of the United States Marine Corps falls for administrative purposes under the US Department of the Navy, the USMC is militarily a separate armed service - they aren't 'the Navy's marines' unless you regard the suits as 'the Navy'... as a naval man yourself, Lewis, I doubt this is a precedent you'd want to set!