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> I have [...] a 10mm Is that a gun in your pocket or are you pleased to see me but underwhelmingly endowed? More seriously, I assume that's the bore of a gun

> I have [...] a 10mm Is that a gun in your pocket or are you pleased to see me but underwhelmingly endowed? More seriously, I assume that's the bore of a gun. Coming from a nation without guns (or bears), I don't know what that says about it. Clarification welcome.

mindcrime 3y ago
There are a few different methods for denoting ammunition, but mostly you'll see sizes expressed in mm's, or decimal portions of an inch. Decimal portions of mm's show up as well, in things like "7.62x51" rounds, etc. Often (usually) there will be qualifiers (often the brand name of the first manufacturer of a given round, or the inventor of it). Qualifiers like "Auto", "Magnum", "NATO", etc are also common and have specific meanings. Colloquially in the US, "10mm" corresponds to "10mm Auto"[1] which is a moderately popular handgun cartridge. 10mm rounds are towards the larger / more powerful end of the popular range for handguns, but are still far from what most people would consider "packing for bear". Guns chambered for larger and more powerful rounds are available, but as with everything there are tradeoffs. With 10mm you sacrifice some "stopping power" (a simplistic calculation would be speed in feet-per-second times the mass of the projectile) per-shot, but can probably carry more total rounds, than something larger like, say, .44 Magnum[2] or .454 Casull[3]. So one weighs "would I be better off with n shots with x stopping power, or n-s shots with x*q stopping power, for some number of fewer shots s, and some additional power (as a ratio) q"? Other factors that come into play are cost, recoil, weight of the weapon itself (besides the cartridges), etc. Anyway, net-net, for people who live in bear country, from what I've seen, 10mm is often seen as a good compromise for bear protection. But I'm sure plenty of people prefer the .44 Magnum, the .454 Casull, or even something like .50AE[4]. We have bears where I live, but they're not common-place in this part of the state, and they're mostly black bears, and while they certainly can be dangerous, black bears are the smallest bear species that is common in North America. And at least around here, they still seem to be fairly "human shy" even when encountered. So on the occasions when I carry a pistol in the outdoors, I just go with the same 9mm I carry everywhere else. TBH, I'm not really thinking about bear protection much in those cases... I'm mostly carrying for protection from my fellow humans. shrug [1]: https://en.wikipedia.org/wiki/10mm_Auto https://en.wikipedia.org/wiki/10mm_Auto [2]: https://en.wikipedia.org/wiki/.44_Magnum https://en.wikipedia.org/wiki/.44_Magnum [3]: https://en.wikipedia.org/wiki/.454_Casull https://en.wikipedia.org/wiki/.454_Casull [4]: https://en.wikipedia.org/wiki/.50_Action_Express https://en.wikipedia.org/wiki/.50_Action_Express
- hutzlibu 3y ago
  I am not a gun expert, but isn't raw physical impulse stopping power mostly not that important and it is way more about what you hit? A bigger projectile will just do more damage and hurt more, so that is what will effectivly stop the attacker. Quick calculation with wikipedia data: Impulse Bear: 15 m/s * 410 kg = 6377.7 Ns Impulse 10 mm bullet: 390 m/s * 0.01 kg = 3.9 Ns 6377 - 3.9 = 6373 -> seems not that great of an impact, barely slows him down. But if you hit a leg and the bear will fall - then he is stopped.
  - mindcrime 3y ago
    Yeah, raw ballistic power is just a ballpark number, usually thrown around in "all other things being equal" discussions. Shot placement and other factors absolutely matter as much, or more, when it comes to choosing what firearm to carry for a given situation. But there is usually a "floor" to the amount of ballistic power you want, based on empirical observations over time. Eg, people have noticed that .22LR doesn't tend to work very well for bear defense, so they prefer a larger cartridge, etc. Note too that there are other factors (penetration depth, projectile expansion / fragmentation, etc) that come into play. And with many of those things, there's a lot of folklore around, some science which may or may not carry over (for example, the question of how projectiles fragment in ballistic gel, versus in actual flesh), and no small amount of controversy and debate. If you want to amuse yourself sometime, find a couple of friends who are avid shooters and ask them "which round is the best round for self-defense, vis-a-vis stopping power?" Most likely they'll still be arguing about it 2 or 3 hours later when you quietly slip away to go do something else...
  - COGlory 3y ago
    There's so many considerations to killing an animal that it's impossible to simplify to one thing. That said, if I was forced to, the #1 thing you want a bullet to do is transfer as much energy to the animal as possible. All else being equal, big bullets carry more energy. Therefore, they transfer lots of energy. Yes, some smaller rounds expand upon impact and tramsfer lots of energy, more efficiently as well, but the problem is that they may expand in fat or bone, before hitting vital organs. So they might not work as well. In a bear charging scenario, you aren't precisely aiming. You are praying your bullets make it past the extremely dense bones and wipe out vital organs. The best way to do this is big bullet travelimg fast. P.S. - when people say stopping power, they usually mean stopping the animal's heart. This is basically the ability to transfer energy to vital organs, which is a combination of penetration and energy transfer.

mindcrime 3y ago

There are a few different methods for denoting ammunition, but mostly you'll see sizes expressed in mm's, or decimal portions of an inch. Decimal portions of mm's show up as well, in things like "7.62x51" rounds, etc. Often (usually) there will be qualifiers (often the brand name of the first manufacturer of a given round, or the inventor of it). Qualifiers like "Auto", "Magnum", "NATO", etc are also common and have specific meanings. Colloquially in the US, "10mm" corresponds to "10mm Auto"[1] which is a moderately popular handgun cartridge. 10mm rounds are towards the larger / more powerful end of the popular range for handguns, but are still far from what most people would consider "packing for bear". Guns chambered for larger and more powerful rounds are available, but as with everything there are tradeoffs. With 10mm you sacrifice some "stopping power" (a simplistic calculation would be speed in feet-per-second times the mass of the projectile) per-shot, but can probably carry more total rounds, than something larger like, say, .44 Magnum[2] or .454 Casull[3]. So one weighs "would I be better off with n shots with x stopping power, or n-s shots with x*q stopping power, for some number of fewer shots s, and some additional power (as a ratio) q"? Other factors that come into play are cost, recoil, weight of the weapon itself (besides the cartridges), etc. Anyway, net-net, for people who live in bear country, from what I've seen, 10mm is often seen as a good compromise for bear protection. But I'm sure plenty of people prefer the .44 Magnum, the .454 Casull, or even something like .50AE[4]. We have bears where I live, but they're not common-place in this part of the state, and they're mostly black bears, and while they certainly can be dangerous, black bears are the smallest bear species that is common in North America. And at least around here, they still seem to be fairly "human shy" even when encountered. So on the occasions when I carry a pistol in the outdoors, I just go with the same 9mm I carry everywhere else. TBH, I'm not really thinking about bear protection much in those cases... I'm mostly carrying for protection from my fellow humans. shrug [1]: https://en.wikipedia.org/wiki/10mm_Auto https://en.wikipedia.org/wiki/10mm_Auto [2]: https://en.wikipedia.org/wiki/.44_Magnum https://en.wikipedia.org/wiki/.44_Magnum [3]: https://en.wikipedia.org/wiki/.454_Casull https://en.wikipedia.org/wiki/.454_Casull [4]: https://en.wikipedia.org/wiki/.50_Action_Express https://en.wikipedia.org/wiki/.50_Action_Express

hutzlibu 3y ago
I am not a gun expert, but isn't raw physical impulse stopping power mostly not that important and it is way more about what you hit? A bigger projectile will just do more damage and hurt more, so that is what will effectivly stop the attacker. Quick calculation with wikipedia data: Impulse Bear: 15 m/s * 410 kg = 6377.7 Ns Impulse 10 mm bullet: 390 m/s * 0.01 kg = 3.9 Ns 6377 - 3.9 = 6373 -> seems not that great of an impact, barely slows him down. But if you hit a leg and the bear will fall - then he is stopped.
- mindcrime 3y ago
  Yeah, raw ballistic power is just a ballpark number, usually thrown around in "all other things being equal" discussions. Shot placement and other factors absolutely matter as much, or more, when it comes to choosing what firearm to carry for a given situation. But there is usually a "floor" to the amount of ballistic power you want, based on empirical observations over time. Eg, people have noticed that .22LR doesn't tend to work very well for bear defense, so they prefer a larger cartridge, etc. Note too that there are other factors (penetration depth, projectile expansion / fragmentation, etc) that come into play. And with many of those things, there's a lot of folklore around, some science which may or may not carry over (for example, the question of how projectiles fragment in ballistic gel, versus in actual flesh), and no small amount of controversy and debate. If you want to amuse yourself sometime, find a couple of friends who are avid shooters and ask them "which round is the best round for self-defense, vis-a-vis stopping power?" Most likely they'll still be arguing about it 2 or 3 hours later when you quietly slip away to go do something else...
- COGlory 3y ago
  There's so many considerations to killing an animal that it's impossible to simplify to one thing. That said, if I was forced to, the #1 thing you want a bullet to do is transfer as much energy to the animal as possible. All else being equal, big bullets carry more energy. Therefore, they transfer lots of energy. Yes, some smaller rounds expand upon impact and tramsfer lots of energy, more efficiently as well, but the problem is that they may expand in fat or bone, before hitting vital organs. So they might not work as well. In a bear charging scenario, you aren't precisely aiming. You are praying your bullets make it past the extremely dense bones and wipe out vital organs. The best way to do this is big bullet travelimg fast. P.S. - when people say stopping power, they usually mean stopping the animal's heart. This is basically the ability to transfer energy to vital organs, which is a combination of penetration and energy transfer.