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Weapon *Life Expectancy*

Discussion in 'Weapons & Technology in WWII' started by Totenkopf, Aug 17, 2010.

  1. Totenkopf

    Totenkopf אוּרִיאֵל

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    Just a bit of thinking aloud here, but did Small arms have a sort of *expire date* in the sense of the barrel and internals being worn down to due friction generated from use in a similar fashion to that of artillery and mortars?

    I do understand that efficiency generally went downhill from Day 1 in Long range guns as it made alot of heat to propel the round out of the barrel, as well as further friction from metal on metal.

    But then there is the case of the MGs that needed a barrel change because of their huge fire rates which had a risk of the barrels turning into molten slag, what effect did this incredible wear have on the internals of the guns?

    Any thoughts or info would be appreciated.
     
  2. brndirt1

    brndirt1 Saddle Tramp

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    Well I suppose it should be looked at in the vein of what was the weapon supposed to do? A wheel gun (revolver) will last longer than an automatic pistol, a bolt action rifle will last longer than a semiautomatic. And in the SMG area, there were some real "throw-away" types, with very limited quality control. These were just "lead pumps".

    But a great many of the machine guns were designed for long life, and duration of the internal parts. Those would be well machined, and quality produced just because of the time they were expected to function. The MG-42 was able to outlast many, MANY of its barrels without failing or coming apart.

    And while the Browning designs didn't have the "barrel change" ease of the BREN or the MG-42, it too was designed to last a LONG time.

    The Browning MGs were so reliable that the Army called off the tests of one of his first designs after it had fired without jam or mis-fire for many tens of thousands of rounds. That was the first test of the prototype water cooled 1917 Browning .30 caliber MG, but the Army demanded a second test.

    In the second test, Browning fired the weapon in two lengthy bursts of 20,000 rounds each without a single mishap. The Ordnance Board was unconvinced that the same level of performance could be achieved in a production model.

    So Mr. Browning produced a second weapon which he fired in a third test continuously for 48 minutes (over 21,000 rounds) without a misfire, internal parts breakage or jam. I think the brass just got tired of waiting around for something to go wrong and called the test off.

    Here is a good starting place for information on his designs, but it also has sublinks to Kalashnikov and Maxim designs as well.

    Goto:

    Browning Machine Guns

    Don’t know about all the other small arms shelf life, but until that test with the Browning MG in 1917, the Browning/Colt 1911 .45 ACP was the American record holder for uninterrupted firing duration.

    I am sure there were many weapons made by the Allies as well as the Axis which were far from "wear proof". The Japanese Type 100, the STEN, and PPSh-41 come to mind, and the M3 "grease gun" wasn’t a precision made weapon either.
     
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  3. OpanaPointer

    OpanaPointer I Point at Opana Staff Member WW2|ORG Editor

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    It was based on visual inspection for the most part, as far as I know. When the rifling got rounded it was time for a new barrel. For anything else, interchangeable parts ruled.
     
  4. T. A. Gardner

    T. A. Gardner Genuine Chief

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    Yes, most weapons have a life expectancy. With larger weapons like artillery pieces and such this is measured in a certain number of rounds before the barrel or barrel liner has to be changed. Typically this is somewhere between a few hundred (very large guns) and thousand (small ones) rounds.

    For small arms they do wear out. This usually takes thousands of rounds fired from the weapon. The problem was endemic in some US units issued WW 2 weapons for Korea. They found these were worn well beyond their replacement point and often failed to work properly. BARs and Carbines were two of the most commonly encounted rifle caliber weapons that had this problem in Korea.
     
  5. Poppy

    Poppy grasshopper

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  6. Proeliator

    Proeliator Member

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    20,000+ rounds in one long burst without a barrel change? That thing must have been a smoothbore in the end :lol: But still very impressive if there wasn't a single missfire or cook-off, esp. seeing as it was a closed bolt firing design.

    IIRC the various armies around the world expected their rifle barrels to last from between 6,000 to 10,000 rounds, but not in one long burst ofcourse.The actions lasted a lot longer ofcourse.
     
  7. formerjughead

    formerjughead The Cooler King

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    It was water cooled so as long as there was water circulating through the condensor, and water jacket, the barrel shouldn't have gotten much hotter then 212 degrees(F).
     
  8. Proeliator

    Proeliator Member

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    Are you sure one could maintain that barrel temperature without having to stop at some point and refill the water jacket and evap unit? I mean 20,000 rounds at 450 rpm is 45 min of continoues fire. I've never tried firing one of those machine guns for so long before, so I wouldn't know.
     
  9. formerjughead

    formerjughead The Cooler King

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    It was a sealed unit, so as long as the heat from the barrel created steam causing it to draw from the water tank and return there should have been no reason to change the water or the tank. Think of it like the radiator on your car: You only have to add water when there is a problem.
     
  10. TiredOldSoldier

    TiredOldSoldier Ace

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    Don't know about the Browning but the Wickers when used for continuos suppression fire needed to be refilled with water, there are pictures of British MG units surrounded by water vapor clouds, IIRC this could be done without stopping fire, they simply attached a can with a tube to the refil cap and kept pouring in water.
    IMO even without jams wear on the barrel rifling would be an issue after 20.000 rounds, in such an extreme scenario I think the quick change air cooled weapons would have an advantage, though taking one gun at a time off line to change barrels is a possibility, never read anything like that though, was it done?
    MG suppression fire only makes sense to cover advancing troops and you don't want to be shooting a smoothbore close to your men though probably adding a few tracers to the belts will allow for correction as barrel characteristics change with wear.
     
  11. Proeliator

    Proeliator Member

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    No you definitely had to refill the unit with cold water at some point, it wasn't an infinite cycle ;) The question however is when did you need to refill it = I would think a lot sooner than after 45 min of firing.
     
  12. lwd

    lwd Ace

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    I seem to remember reading of them using urine as a substitute for "cold" water on occasion. This was obviously in an emergency but I doubt they had been firing continuously for as long as the tests mentioned.
     
  13. formerjughead

    formerjughead The Cooler King

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    I think we need to establish what the conditions of the testing were.

    I do stand corrected: it was not a sealed unit, the cooling hose was simply placed in the can of water or 'coolant'. The vacuum created by the steam created would pull fresh 'coolant' from the can. I am sure that when they reloaded the weapon, during the tests, that they were allowed to change the coolant can as well.
    The ammunition was supplied via a 250 rd cotton belt and not the latter disintegrating link.

    Sorry for any confusion my assumptions caused.
     
  14. Poppy

    Poppy grasshopper

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    I'd heard that sometimes, when in need, they might drink the water ( you'd hope ) out of the water jacket? Eww.
     
  15. sf_cwo2

    sf_cwo2 Member

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    Life expectancy for weapons & equipment was based on the average time until a part needed repair or replacement. This could be the result of neglect, general use, or damage from combat. For example, a schwimmwagen had a combat life expectancy of 6 weeks. The kubelwagen's was longer because body integrity was not crucial to its performance. Firearms like the FG42 and BAR (ie., barrels permanently mated to the receiver) were scrapped for parts once the barrel hit a fixed round count or reached max erosion measurements. Other weapons were scrapped when the receivers stretched too thin. A listing of required spare parts would give you a good idea of which part determined the life expectancy.
     
  16. Poppy

    Poppy grasshopper

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    Nice bit SF. But how would they know when the "fixed round count " was due? How would they measure the erosion? Would they need some kind of caliper to measure or would the average GI be able to tell just by gawking at it?
     
  17. Triple C

    Triple C Ace

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    Was there any reason why M-1 carbines wore out whereas other weapons did not? A higher practical rate of fire maybe?
     
  18. lwd

    lwd Ace

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    Someone with experiance can tell it's time to mike it by looking at it. Whether or not you actually bother depends a lot on the situation. If you are about to go into combat and new ones are available then if it looks bad it's probably replaced. If you are on garrison duty somewhere and replacements are dear then even if it mikes bad it may not be replaced or it may take considerable time to do so.
     
  19. formerjughead

    formerjughead The Cooler King

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    There are a series of visual and physical inspections that are done to the weapons at varying frequency. Most of the visual inspections are done by the operators as part of regular maintenance when the weapon is disassmebled and cleaned. Once the weapon is cleaned and reassembled a 'function check' is performed, a similar check to this is the movement in the 'Manual of Arms': "Inspection Arms".

    During WW2 when troops were rotated off the line there weapons would be inspected by the unit Armorers. During an armorers inspection things such as barrel ware, chamber wear and head space are checked and this is done with two gauges; one is a long rod that slips down the barrel and measures head space with one end and barrel ware with the other and each has a "GO/No GO" measure. The next is a 'Slug' which is chambered in the action and measures chamber and throat ware, again one direction is "GO" the other is "NO GO". There are other inspections that are performed these are just a couple of examples.

    Here is a link to the "Fulton Armory" and they have several of the gauges I am referring to:
    Tools & Accessories

    I am sure that the Airforce and Navy performed similar inspections on the Aircraft weapons systems more frequently. On the bigger weapons there is actually a schedule of maintenace in the corresponding "10 Manual" for what should be done at different intervals.
    When I was in the Marines there were quarterly Armorer's Inspections. When I was in the National Guard (Armorer) there were Bi-Annual and Annual inspections in addition to monthly and quarterly that we would have to perform and document.

    The .50 Cal that we had in my Guard unit was circa 1945 built by 'AC Spark plug' and it is currently in Afghanistan or en route as we speak.
     
  20. sf_cwo2

    sf_cwo2 Member

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    Are you new to firearms? Every military firearm has a mind-boggling number of tools, gages, and accessories to keep it functioning. Just buy a cheap armorer's manual and it will give you an idea of what he could do and with what. BTW for every 1 trigger-puller in the field ~ 5 more personnel are deployed to support his "stay". This includes medics, clerks, mechanics, cooks, armorers, etc....
     

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