Quick change barrel MGs developed before WW1

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Deleted member 1487

From what I've been able to find quick change barrels were only developed after WW1 during the interwar period, which left WW1 MGs with heavy water cooling mechanisms to keep their weapons operational. Despite having relatively light weight LMGs already in service for the air force, their use on the ground was limited due to their tendency to overheat quickly. Quick change barrels would have dramatically improved performance for all MGs, while making them light enough to be used at the squad level for maneuver in LMG form or easier to displace for the more fixed MMG/HMGs either for retreating, moving to take advantage of a tactical situation, or simply repositioning away from enemy fire. Weapons like the Lewis Gun could have been much lighter and more like the best of the WW2 LMGs like the Bren Gun.

So how would the maneuver campaigns of 1914 have been influenced by the existence of much lighter MGs that could keep up with the infantry, rather than being a more fixed defensive weapon that only became relative offensive and maneuverable late in WW1? Could it have helped with WW1 offensive in trench warfare situations if especially early on MGs could keep up with attacking infantry and also maintain sustained fire so long as ammo held out (with more being able to be carried thanks to the lighter weapons)?
 

SwampTiger

Banned
You have answered your own question. Better magazines or belt systems would help. Fire power can now advance at the pace of the infantry. You will still out pace the artillery. The force with light, mobile machine guns will have a temporary advantage. Overall, it may not make much difference. Thus, depending on which army has the advantage, the trench lines will move from OTL. The first force to develop infiltration/small unit/fire based tactics may move the trench lines better than OTL. However, artillery movement will remain the limiting factor.

You do know take down guns have been available since the late 19th Century. Both the Remington Model 8 rifle and Winchester Model 12 shotgun were take down guns, i.e., you disassembled them for transport. The process was not always simple. Just have someone put the concept together earlier.
 
From what I've been able to find quick change barrels were only developed after WW1 during the interwar period, which left WW1 MGs with heavy water cooling mechanisms to keep their weapons operational.

The Chauchat with it's long recoil operation, would have been possible to have a quick change barrel system, had it used the Browning Model 8 system of having the recoil spring around the barrel, and a cam lock rather than a screw
model8takedown3.jpg
 
Both the Remington Model 8 rifle and Winchester Model 12 shotgun were take down guns, i.e., you disassembled them for transport. The process was not always simple

Picture above
Retract bolt
Remove handguard, one screw
that gives access to the takedown screw, with the pivoted lever for mechanical advantage to loosen ot tighten without tools.

For MG usage, you would have cooling slots in the jacket that surrounds the recoil sping, that slides over the barrel.
A cammed lever could replace the screw system.
 

SwampTiger

Banned
I would be very hesitant to use a barrel enclosing spring in a machine gun of any type. Spring tension after a dozen or so heat/cool cycles will decline. Stuff the spring in an
 
From what I've been able to find quick change barrels were only developed after WW1 during the interwar period, which left WW1 MGs with heavy water cooling mechanisms to keep their weapons operational. Despite having relatively light weight LMGs already in service for the air force, their use on the ground was limited due to their tendency to overheat quickly. Quick change barrels would have dramatically improved performance for all MGs, while making them light enough to be used at the squad level for maneuver in LMG form or easier to displace for the more fixed MMG/HMGs either for retreating, moving to take advantage of a tactical situation, or simply repositioning away from enemy fire. Weapons like the Lewis Gun could have been much lighter and more like the best of the WW2 LMGs like the Bren Gun.

So how would the maneuver campaigns of 1914 have been influenced by the existence of much lighter MGs that could keep up with the infantry, rather than being a more fixed defensive weapon that only became relative offensive and maneuverable late in WW1? Could it have helped with WW1 offensive in trench warfare situations if especially early on MGs could keep up with attacking infantry and also maintain sustained fire so long as ammo held out (with more being able to be carried thanks to the lighter weapons)?
You do know take down guns have been available since the late 19th Century. Both the Remington Model 8 rifle and Winchester Model 12 shotgun were take down guns, i.e., you disassembled them for transport. The process was not always simple. Just have someone put the concept together earlier.
The Chauchat with it's long recoil operation, would have been possible to have a quick change barrel system, had it used the Browning Model 8 system of having the recoil spring around the barrel, and a cam lock rather than a screw
This does however require a somewhat significant manufacturing technology advance. Contrary to popular belief, quick-change barrels weren't invented until the 1920's, not because people just didn't think of the idea, but because it could not be done with the technology of the time:
Browning met most of his design objectives but there were two design challenges that he could not achieve. With the machine tools available at that time, the dimensions that established the location of the bolt face and the depth of the chamber could not be held tightly enough to control the fit of the cartridge in the chamber. This important dimension, known as headspace, can cause problems when out of specification. Depending on tolerances, the round could be too tight in the chamber, and the gun wouldn’t shoot at all. At the other extreme, the round was too loose in the chamber which resulted in a stoppage at best; or a ruptured cartridge at worst. The ruptured cartridge presented a serious danger to the shooter, spewing brass shards at high velocity out the bottom of the receiver. Another dimension that couldn’t be held close enough governed when the firing pin would fall – a dimension that later became known as timing.

Since these weapons had to be made on existing machinery, Browning made an easy adjustment that required the operator to screw the barrel into the barrel extension, moving the barrel toward the bolt face to reach the proper headspace. He developed a couple of simple gages that allowed the operator to adjust to the proper dimensions.
http://www.sadefensejournal.com/wp/new-50-cal-machine-guns-no-tanks/
That was the M2 Browning, which until 2012 was the last remnant of adjustable headspace and timing. But in WWI, every machine gun had adjustable headspace and timing; each barrel had just enough differences back then to fit differently. It doesn't matter how fast you can physically change the barrel; you'll spend a few minutes fiddling with the gauges to get the headspace and timing right no matter what. And that was for the Browning M1917 family, which was the best and easiest of those guns to adjust; from what I've seen of Maxims and other WWI actions, they may have almost required an armorer to adjust the headspace and timing.

In a sense, adjusting headspace and timing is a form of hand fitting, and quick-change barrels are a form of interchangeable parts. Like all interchangeable parts they depend on closer tolerances, which didn't exist until after WWI OTL. So to do this improved manufacturing tolerances have to be adopted earlier, which can be hard to do with how much they depend on better technology.
 
It's not as if new technology would be needed, interrupted screw threads were well known. It's how breach blocks were locked in artillery pieces.
 
This does however require a somewhat significant manufacturing technology advance. Contrary to popular belief, quick-change barrels weren't invented until the 1920's, not because people just didn't think of the idea, but because it could not be done with the technology of the time.
...


In a sense, adjusting headspace and timing is a form of hand fitting, and quick-change barrels are a form of interchangeable parts. Like all interchangeable parts they depend on closer tolerances, which didn't exist until after WWI OTL. So to do this improved manufacturing tolerances have to be adopted earlier, which can be hard to do with how much they depend on better technology.
That's for short recoil operation. Long Recoil is a bit different, since the bolt is locked into the barrel until the end of the recoil stroke.

Each barrel, would have had to been previously fitted to that weapon. But after that, could be swapped without worry on headspace.

JMB was a great designer, but the M1917 and the M2 had issues. Were not perfect.
 

Deleted member 1487

This does however require a somewhat significant manufacturing technology advance. Contrary to popular belief, quick-change barrels weren't invented until the 1920's, not because people just didn't think of the idea, but because it could not be done with the technology of the time:

http://www.sadefensejournal.com/wp/new-50-cal-machine-guns-no-tanks/
That was the M2 Browning, which until 2012 was the last remnant of adjustable headspace and timing. But in WWI, every machine gun had adjustable headspace and timing; each barrel had just enough differences back then to fit differently. It doesn't matter how fast you can physically change the barrel; you'll spend a few minutes fiddling with the gauges to get the headspace and timing right no matter what. And that was for the Browning M1917 family, which was the best and easiest of those guns to adjust; from what I've seen of Maxims and other WWI actions, they may have almost required an armorer to adjust the headspace and timing.
Note that the quote does say 'with existing machinery' rather than machinery that could have been procured; he was limited to what machinery they were already building the weapons on. There was a French MG that was relatively 'quick change' compared to that of day, which still required a special wrench to perform the work:
https://en.wikipedia.org/wiki/Hotchkiss_M1914_machine_gun
The gun could sustain continuous firing of about 120 aimed shots per minute almost indefinitely,[8] except for occasional barrel changes (during continuous fire, approximately every 1,000 rounds) which were quick and easy to perform with a special wrench.
So this does imply that it was available technology if it were developed a bit further.
 

Deleted member 1487

You have answered your own question. Better magazines or belt systems would help. Fire power can now advance at the pace of the infantry. You will still out pace the artillery. The force with light, mobile machine guns will have a temporary advantage. Overall, it may not make much difference. Thus, depending on which army has the advantage, the trench lines will move from OTL. The first force to develop infiltration/small unit/fire based tactics may move the trench lines better than OTL. However, artillery movement will remain the limiting factor.
I wonder if it might not make the defender even tougher to deal with, as they can maneuver their MGs and keep up fire with LMGs, unlike the OTL models; when the Germans introduced the MG08/15 in 1917 at Chemin des Dames the French suffered unexpectedly badly even after their successful offensive experience at Verdun. Granted there were any number of other factors in play, but one of the bits that contributed was the introduction of elastic defense, something predicated on the ability to have mobile firepower for counterattacks or mobile defense, which their 'light' machine guns enabled. Since the MG08/15 was 18kg something closer to the air cooled model introduced in 1918 with a 10-12kg weight, even accounting for the weight of extra barrels, would still save a heap of weight that would make the teams more mobile and each unit cheaper.

Of course that also means that the French could have something much better than the less than ideal Chauchat, which would be a pretty big help compared to OTL.
 
You want an LMG in WWI then you want a Lewis or Madsen. A Lewis without the shroud and with a quick change barrel would be ideal. Even a B.A.R. is outclassed by the Lewis, let alone the Chauchat.

 
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Of course that also means that the French could have something much better than the less than ideal Chauchat, which would be a pretty big help compared to OTL.

Even just having decent QC at the various factories, and even just to have guns actually be fully interchangeable within the same factory without 'fitting' would be an improvement.

These definitely were not like M1 Carbines, where you could take an dissembled unit from each of the subcontractors, mix up all the parts, and get fully operating guns from all the jumbled up bits after reassembly.
 

Deleted member 1487

Even just having decent QC at the various factories, and even just to have guns actually be fully interchangeable within the same factory without 'fitting' would be an improvement.

These definitely were not like M1 Carbines, where you could take an dissembled unit from each of the subcontractors, mix up all the parts, and get fully operating guns from all the jumbled up bits after reassembly.
Sure, but even going by the youtube project above the Chauchat was even worse in operation than gun experts thought it would be. They said they basically couldn't hit anything with it and that was a working model.
 
It's not as if new technology would be needed, interrupted screw threads were well known. It's how breach blocks were locked in artillery pieces.
Note that the quote does say 'with existing machinery' rather than machinery that could have been procured; he was limited to what machinery they were already building the weapons on. There was a French MG that was relatively 'quick change' compared to that of day, which still required a special wrench to perform the work:
https://en.wikipedia.org/wiki/Hotchkiss_M1914_machine_gun

So this does imply that it was available technology if it were developed a bit further.
Yes, but just attaching the barrel to the gun faster doesn't in itself change the need to adjust headspace after that.

That's for short recoil operation. Long Recoil is a bit different, since the bolt is locked into the barrel until the end of the recoil stroke.

Each barrel, would have had to been previously fitted to that weapon. But after that, could be swapped without worry on headspace.
That's not the case. If a new barrel is fitted for the first time, the gun is adjusted to that and then it won't fit the old barrel anymore (and can't be swapped back without adjusting again). As a result each gun can only be fitted to one barrel at a time, because each barrel was just a bit different with the older tolerances.
 
That's not the case. If a new barrel is fitted for the first time, the gun is adjusted to that and then it won't fit the old barrel anymore (and can't be swapped back without adjusting again). As a result each gun can only be fitted to one barrel at a time, because each barrel was just a bit different with the older tolerances.
That's backwards. you try to do all the adjustment on the barrel to match the current bolt and receiver, when possible for doing a matched set for multiple barrels for a single gun.
That's how the MG-34 did it, a rotating bolt that locks into the barrel, not so different from the Model 8
 
My musings

Lighter MG’s and LMG’s earlier probebly means more MG’s earlier. This increase in firepower would allow less men to hold a length of the line. This results in deeper defences and lower casualties. Also the ability to put down large volumes of suppressive fire might reduce casualties in attack, or at least cancel out increased casualties that more MGs in the defence might cause.

I agree that in itself it makes little difference as infantry will still run out of options once the out run their artillery support. Although marrying LMGs and light mortars might allow infantry to generate enough internal firepower to overcome less well established defences.
 
A Lewis without the shroud and with a quick change barrel would be ideal.

There was a prototype lightened and shortened Lewis gun called the BSA Light Infantry Pattern that weighed iirc 17 to 19 pounds unloaded. I think it was one of those weapons that got cancelled because it was going to be too late for the war.

This is a picture of a later version of the BSA Lewis which was in the trials that eventually led to the Bren
british-small-arms-development-the-inter-war-years-27-638.jpg

Taken from a slide show by the historical breechloading small arms association

https://www.slideshare.net/tcattermole/british-small-arms-development-the-inter-war-years
 
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