• M0oP0o@mander.xyz
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    6 days ago

    Ma Deuce has to change barrels after getting too hot, these Maxims can fire forever if you keep them topped up with water and/or piss.

    • prettybunnys@piefed.social
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      6 days ago

      Ma Deuce gets to hot swap barrels to keep it firing well beyond when everyone’s out of water and piss.

      Most notable accolade for Ma:

      In service: 1933-present

      • CanadaPlus@lemmy.sdf.org
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        6 days ago

        Man, you have a lot of barrels if you run out of water and piss first.

        What you’re talking about is effectively finished gun barrels as a coolant, and guys scrambling to change them as cooling system. That’s a little jankier than a small pump or gravity feed and the most common fluid on Earth.

        • prettybunnys@piefed.social
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          6 days ago

          All joking aside the barrel weighs less than the cooling system and running out of water was a very real concern. You’d run out of water before bullets.

          So it’s easier to carry and stock barrels than it is to carry the heavy ass water cooled gun. There IS a reason the air cooled gun was chosen over water cooled.

          • CanadaPlus@lemmy.sdf.org
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            6 days ago

            Well obviously, you should cool it with the other bullets, then. Maybe you could even collect the spent ones for that. /s

            If directly using air is fast enough, sure, that’s a better option. I mean, in a water cooled gun, the water/steam itself gets cooled in the air, or on surrounding surfaces. It’s just an intermediary to increase effective surface area.

            Not actually knowing much about the history of this, just the science, it seems likely that a barrel replacement was expected to be a rare event, because the rate of fire and heat per shot was low enough for whatever other engineering features to handle it, at least most of the time.

            • PuddleOfKittens@sh.itjust.works
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              5 days ago

              Roughly speaking you’d need to change the barrel every ~1000 rounds, and WW1 MGs shoot at ~200 rounds per minute, so you’d need to swap the barrel once every 5 minutes of continuous shooting. It could be half of that tho, depending on the barrel and the gun.

              • CanadaPlus@lemmy.sdf.org
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                3 days ago

                I guess if holding the trigger down for 5 straight minutes is going to be an absolute survival necessity in any war, WWI might be it. But it still sound unusual. 2 minutes does seem more realistic for whatever confrontation in nomansland, although if that happens often, having to stop and change barrels would really matter.

                The thermal mass of steel is about 490 joules per kilogram per degree Celsius/Kelvin, for reference, while water gets 4181 at 25C. That means for the same capacity to absorb heat, you’d need to carry about 8.5 kilograms of gun barrels for every one kilogram of piss. Water cooling is so fast it’s usually treated as instant, so thermal conductivity hardly matters. Steel can get a lot hotter than water before it changes phases, that’s true, but at some point your barrel is going to have thermal expansion and heat softening problems, as well.