Weapon *Life Expectancy*

Shotgun powders don't necessarily burn at the same rates as rifle powders, or at least those which are "factory loads". Then also, the pellets are contained in a "cup" now-a-days it is plastic but it used to be paper/cardboard. Then the pellets aren't the only thing in the cup either, they share the space with tiny bits on lighter material to keep the pellets separated and make the "pattern" less random when the cup exits the barrel. As to tracer rounds, I wouldn't have a clue.

 

And what claims would that be lwd? That their barrels wouldn't last for 20,000 rounds of non-stop firing? I think that has been proven quite clearly, esp. considering the highly erosive powders used back then. Add to this that the barrels of WW1 machine guns weren't coated or anything and you can be sure they wouldn't last for 20k rounds of non-stop firing, that is for sure. You are welcome to believe otherwise ofcourse..

Wrong. The document you posted suggested an average barrel life of ~15,000 rounds if the gun was properly operated; squeezing the trigger and not letting go before 20k rounds have been fired is not operating it properly.

Shooting 20k rounds of WW1 period ammunition through the M1917 with the only breaks taken being 10 secs to changes belts would ruin the barrel before the first 10,000 rounds, I have no doubt about it. Water is a good heat conducter, but there are limits to everything.

Infact I am reading a British WW1 account right now that states that their water cooled Vickers started overheating after just 2 min of non-stop firing.

 

No it's not proven. It's possibly correct but it still just your opinion.

Not at all. Note that it didn't say that the barrels were useless after that many rounds were fired. It indeed suggested that they be checked in a couple of different ways. Furthermore you have yet to demonstrate that long burst were imporper use for a watercooled mg. I strongly suspect that the reason continuous fire is so hard on barrels is that over heating them essentially aneals them makeing them less ware resistant both while hot and if they get hot enough permenantly so. There is no particular reason that corrosive ammon would have an effect that get so much worse with burst size that I can see.

 

It's never easy to prove a negative lwd.

You have misunderstood something lwd. First of all the ammunition used back in WW1 wasn't just corrosive, it was also highly erosive to the barrel during firing as-well, and that because of a very high flame temperature. As a result barrel wear was much worse back then than it is now, infact powder manufacturers claim that useful barrel life have increased more than 10 times since WW1.

The proof has been presented by even yourself, noting an average barrel life of 15,000 rounds through proper operation of the gun, i.e. 15k rounds fired over several weeks, months perhaps even years. Firing the gun non-stop however is not operating it properly, and would lead to the barrel's demise rather quickly.

lwd, I have yet to see a single machine gun barrel that could take 20k rounds going through it in one go before becoming a scatter gun; and I am sure no'one else in here has either.

 

Then why are you so certain?

Did you note the date of the reference I posted? I believe it was 1921. Are you saying there was a big change in powder between WWI and 1921? As for high flame temperatures care to state just what they were?

The fact that a barrel could last 15,000 rounds or more certainly suggest 20,000 is possible. You have yet to produce any data as to how much worse continuous firing in a water cooled mg would be. Thus your hypothesis is unproven.

That you haven't doesn't really mean much to me. As for any one else here that's a different matter but it's still not all that relevant as water cooled maching guns have been out of service for some time.

 

Like how this thread initially was a broad question, then was filtered down into nuts and bolts. Really enjoy the intelligent back and forth. Sometimes learnin' is good readin'... Voted on this thread.

 

Because I quite simply don't believe it can be done lwd, not in one long burst of fire.

I took note of the date, but again we're talking rounds accumulated over several weeks, months maybe even years, and not in one go as is being discussed.

As for the flame temperatures, isn't it abit silly to be asking me for such a thing? Unless ofcourse you have a reference point with which you intend to compare it? Anyway it's not like I've been out measuring flame temperatures of various powder types before, so you're better off just asking the powder manufactures about that one, they are the ones claiming it after-all, and you'll have to excuse me for believing them.

Again, 15,000 rounds spanning over a very long period of time, weeks, months or years. You can't even begin to compare that to the longevity of the barrel when subjected to one long burst of continuous fire.

First of all thanks for just dismissing my personal experience, apparently it means nothing wether you've seen dusins of MG's overheat before or that you've changed barrels on rifles plenty of times due to wear... but if anyone in here has experienced a machine gun go through 10 to 20k of rounds of ammunition in one go and the barrel was OK afterwards, then please do share!

I am not going to pretend I know everything there is to know about machine guns, but the limited experience I have with them is definitely enough for me to know that they will not spit out 20k rounds of ammunition without completely drilling the bore in the process.

 

Fine, as long as you don't exect the rest of us to take your beliefs as the defintive answer.

Indeed but you have yet to produce any signifcant references to show how much difference this would make in a water cooled mg.

Not from someone who seems to be so sure of things. I know that the armaments engineers do take such measurments and I've seen the results of extreme combustion temperatures on tank barrels. However that's not really what we are talking about here. I see two possible mechansims of barrel errosion:
1) Friction.
2) Chemical
In order to predict the impact of continuous fire vs non continuous you have to show how at least one of these is going to be a lot worse. You simply haven't done so. As long as the flame temperature is in the reasonable range for the barrel in normal use for instance it's only if it becomes over heated that continuous fire will make it worse and there is still the question of how this affects water cooled mgs. You simply haven't sourced any data on it.

Actually you should be able to note the difference and make a fairly reasonable comparison. Not all that different from the way battleships barrels are listed as having a life of so many AP rounds where other rounds or different loads are given different wear equivalants as were improved propellents.

Since I have absolutely no idea just what youre experiance is you are quite welcome.

Strawman and not particularly relevant to water cooled mgs in any case.

When what you "know" is based on what you believe be prepared to be challenged on it and not to surprised when what you "know" doesn't correlate with reality. Note for instance your earlier claims that a few hundred rounds would wear out a barrel.

 

No one except for you is arguing that the barrel, after the test, sould be servicable. The test was not to determine the quality of the barrel; it was to prove the action. Accuracy did not play a role in this particular test. This was a test to find the fail point or at which point a malfunction would occur.

Accuracy did not play a role in this test

 

What? Where did I say they would only last for a couple hundred rounds?

The only thing similar I can remember was regarding the M60, where it was noted that barrels needed be changed every 250 rounds of continious fire or the barrel would wear out. I didn't say that the barrel was finished after 250 rounds. But if you kept the trigger down after 250 rounds I'd expect the barrel to start taking damage, and at 500 rounds it would be very very hot. By 1,000 rounds accuracy has taken noticable damage, and by 1,500 rounds you're probably keyholing.

I've ruined an MG3 barrel in just under 1,000 rounds fired, so.... was a fun day at the range.

 

If that were the case then why did people object when I commented that it definitely wasn't shooting straight anymore at 20,000 rounds?? I said nothing about the action taking damage or anything, all I said was that the barrel would've been finished, and that long before the 20,000 rounds had all been fired.

 

Then you must have had a **** barrel, or **** maintenance. A proper MG-3 barrel won't be broken after 'just under 1,000 rounds fired'.

Since 1996 I have only broken one barrel, and that was my fault, and my fault alone. I dropped the barrel out of the case during an advance, and it fell red hot into the snow.

Even the inferior turkish barrels can cope with proper abuse.

 

No everyone stated objecting when you proposed that '03 Springfields would be worn out after 1,000 rds.

If you wore out a barrel on a G-3 in less than 1,000 rds you were firing like a knucklehead or the barrel had other issues. You do realize that training at a military firing range is considerably different than a civilian 'Blast Ex' ?

 

In reference to this statement:

It's kind of hard to give much weight to such nebulous claims as you've made. Then when you finally make some thing substancive such as:

Others point out that there are problems with this claim. Furthermore in regards to the issue at hand it's not at all clear how valuable experiance with a modern mg is when discussiing a early 20th century water cooled maching gun.

In regards to:

Where did I say anything about a "couple of hundred"? I believe I said a "few hundred" few implies more than 1 and usually more than two but a small number. I usually use it for 3-12 but I've seen it used for larger numbers. In this case you've said:

1,000 = 10 x 100 I consider 10 to be a few.
And

500 = a few hundred. And no your personal experiance isn't what counts the most. Especially when you admit that you don't have any relevant experiance as above.

Note the reference which I'll give again states that corrosive/errosive powders weren't the problem in barrel wear.
Ordnance - Google Books

There are of course parts to this issue one is experiance the other is the ability to correctly interpret the same. While I'm not all that sure you have a lot of relative experiance to the topic at hand I'm deeply suspicious of your ability to correctly interpret things. Using superlatives to describe statistical phenomena such as you are prone to do is a serious problem in my book. Take for example the source above. It mentions 15,000 rounds as a point where some barrels need to be examined and their usage in certain circumstances curtailed but notes that barrels have lasted for 17,000 round and even they don't fit the critieria for use in overhead firing are not useless. Based on the above I certainly would not rule out that a barrel as used in the test we are discussing could still be usefull after that point. Certainly one would expect some decrease in both mv and accuracy but it's far from clear that it would be useless. Indeed if one repeated the test enough times I would expect to see one or more barrels reach the end of the test and still have some utility. Just as I would expect some to reach the end of their useful life well before the conclusion of the test.

 

Guys cut the "if you ruined a barrel in 1,000 rounds you're an idiot" attitude, we knew it was going to happen eventually, it was deliberate.

The trigger wasn't released even once, it was a ~1,000 round belt manually put together, and I had to stop before the belt was finished. The barrel was a done deal afterwards.

And the reason I mentioned it is because I think it bares striking resemblance to the WW1 test with the M1917, where it is suggested that over 20,000 rounds were fired non-stop. And so I commented that the barrel definitely would've been completely worn out after that test.

 

There is no problem with it cause it is fact, it's what really happened. Trigger was pulled and it wasn't released until I litterally had to stop.

 

I didn't propose it, it is written down many places formerjughead, and I even provided references for it. Apparently the first powders used in the 30.06 were so erosive that fired in the Springfield the barrel would have useful barrel life of just 1,000 rounds, infact some of my sources claim as low as 800 rounds.

 

Why do you keep confusing corrosive with erosive lwd?

So let me get this straight: You actually believe that the barrel of a watercooled M1917 would be serviceable if it went through 20,000 rounds in one long burst?

You can't be serious??

 

Well thankfully we have become wiser since then:

"With the passing of corrosive primers, erosion from the propellant itself is undoubtedly your barrel’s greatest enemy. When the powder is ignited, it creates extremely hot gases under tremendous pressure. These two factors combine to create erosion, particularly in the throat area of the barrel.

Some older powders, such as DG Pyro or Hi-Vel#2, were very erosive due to their high nitroglycerine content and the resulting high flame temperature. When the 1903 Springfield was first introduced, the original loading of a 220 grain round-nose bullet at 2200 fps gave a useful barrel life of only 800 rounds. This was due to the high nitroglycerine content and resulting high flame temperatures of the powders then in use. As powder chemistry has improved, longer barrel life has been achieved. However, erosion from propellants will probably remain the No. 1 factor in barrel wear in the foreseeable future. This situation is unlikely to change until some radical improvements are made in the chemical makeup of the powder.

Some debate has ensued over the merits of ball powders vs. extruded tubular powders. Extensive testing at Lake City Ammunition Plant found “no significant difference in bore life, accuracy wise, when using either IMR propellants (extruded tubular) or spherical propellants (ball powder).” While these comments were made specifically about the 30 caliber and 7.62mm NATO Match ammunition, the same situation will hold true for most other cartridges."

 

Abit over 900 rounds, no breaks (and unbelievably no stoppages), the barrel was done. And the barrel was not Turkish.

Ideally during bursting fire you swap barrels every 200 or 250 rounds to keep them from wearing up, at the shooting range that day however we decided to have some fun putting together several belts to form a roughly 1,000 round single belt. We fed it in, fired a couple of very short bursts to make sure it was feeding alright, and then I pulled the trigger intending not to let go before the belt was finished - the gun got so hot I was forced to stop before the belt was finished however.