• PugJesus@lemmy.worldOP
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    5 months ago

    So, a derringer is a small pistol, usually with two shots, made for close-range self-defense. Normally they use, well, pistol rounds, like a 9mm, which has like, 700 joules of energy or someshit like that. When you fire a lightweight gun, you definitely get some kickback from it, even with a pistol round.

    A 45-70 is a big-ass rifle round with something like 4000 joules of energy behind it. You uh, you put that in a little derringer and pull the trigger, both you and your target are gonna feel it.

    This also might help put it into perspective

    • justaderp@lemmy.world
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      5 months ago

      Above PugJesus talks about the energy of the round being very large. There’s more to it.

      The derringer design lacks any technology to absorb and extend the impulse of recoil, most importantly the slide found on any modern semi automatic.

      Not only is there extreme recoil, there’s also absolutely nothing to help the shooter deal with it.

      • BearOfaTime@lemm.ee
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        5 months ago

        Does the slide absorb any significant amount of energy?

        The spring can’t be all that strong since they can be assembled by hand, and what does the slide weigh? (Granted the slide is being accelerated, so I assume that’s where the bulk of energy is dissipated, MV^2 and all).

        What’s the math on this, say the dissipated energy in a semi auto VS revolver using the same round?

        (Really I’m curious what the numbers are, as I’ve read this many times but have no idea what the comparison is like).

        • justaderp@lemmy.world
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          5 months ago

          Remember conservation of momentum. The only way the machine can absorb part of the impulse is through friction, heat, and by redirecting the existing chamber pressure after the bullet has left the barrel.

          Remember the human body. Magnitude matters much more than duration. Extending the time of impulse by implementing a slide lessens magnitude, the areas under the impulse curves roughly equivalent.

          I’m going to apply the above to answer your questions to say it again :)

          Does the slide absorb any significant amount of energy?

          For a properly functioning, modern, and typically-designed pistol and a status quo definition of “significant”, the answer is: No. That’s not what it’s designed to do. But, energy can be dissipated slightly if the pistol is compensated: a redirection of chamber pressure from near the end of the barrel, upwards, counter the torque component of the recoil impulse.

          What’s the math on this, say the dissipated energy in a semi auto VS revolver using the same round?

          It’s not quite a good question. The maximum force during the impulse is what a human cares about when analyzing a slide. That’s what’ll effect accuracy of the next round and how sore your hands will be in the morning.

          If minimization of total impulse is what’s being analyzed then one would want to compare rifles. Rifles have larger rounds, longer barrel length thus more time to use chamber pressure to mitigate recoil.

          You’ve good questions for coming into the middle. Go to the beginning: rounds and various types of actions, rifleman 101. Come back to the hard science.

          • BearOfaTime@lemm.ee
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            5 months ago

            Thanks for the thoughtful reply.

            I’ve heard many times that revolvers or semi-auto have less recoil than the other, hence the question about slide mass/energy, as the only element I could see being different which could possibly explain why people hold this opinion.

            Do you know of any actual metrics/tests done that show this clearly? Or is it just a perception issue?

            (And yea, we’d have to agree on a definition of what we’re measuring/comparing). Do any gun magazines run proper tests occasionally to make comparisons?

            I admit my physics classes were a long time ago, but at first glance it seems felt recoil would only be marginally different between a revolver and a pistol using the same round. If anything, I’d expect the revolver to have a greater felt recoil, given the mechanics of a pistol… But I could very well be wrong.

        • ryathal@sh.itjust.works
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          5 months ago

          There is significantly more recoil in a revolver. It’s not just the slide, but the additional weight also helps reduce recoil.

          • raef@lemmy.world
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            5 months ago

            Every revolver I’ve ever held has been heavier than a similar semi-auto. The cylinder is rather massive

    • BearOfaTime@lemm.ee
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      5 months ago

      Do they typically even use something with as much energy as a 9mm? I thought they were typically smaller rounds like 38 or 22, since it’s a close range gun?

      I really don’t know anything about them, would be interesting to see a chart of them.

      • PugJesus@lemmy.worldOP
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        5 months ago

        Mostly I was just grabbing a pistol cartridge that I was vaguely familiar with to demonstrate the difference between a ‘normal’ round for a handgun and a 45-70.

    • NeatNit@discuss.tchncs.de
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      5 months ago

      Thanks :)

      Why the %^&* does that huge bullet even fit and work in that pistol? From the pic it’s obvious the 45-70 is so much wider than the 9mm

    • skillissuer@discuss.tchncs.de
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      5 months ago

      modern loadings do that, but the original loadings were black powder and had energy comparable with today’s 5.56. 5.56 still has much less recoil because it’s lighter

    • Pacmanlives@lemmy.world
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      5 months ago

      Make me wonder how it would compare to a 410 round. I have shot those and they were not fun in a pistol. That pistol was considerably heavier then a Darringer too