# Please explain bullet sizes for guns (and other ammo jargon) **URL:** \ **Category:** Factual Questions\ **Created:** [June 10, 2022, 10:49am UTC](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964 "2022-06-10T10:49:23Z")\ **Posts on this page:** 20\ **Page:** 4
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [June 13, 2022, 8:21pm UTC](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964/61 "2022-06-13T20:21:09Z")
> [@ParallelLines](#): > > So yes, I am clear that a 9mm can be dangerous in the exact same way. The number of quality expanding rounds for reduced penetration in modern defensive ammo is helpful, but not a magic bullet (pun intended) by any means [[Glaser](https://en.wikipedia.org/wiki/Glaser_Safety_Slug) being my favorite ]. But I still find the 5.56, with it’s higher base range a much bigger risk than 9mm, and only recently has that round begun to have the same sort of tricks to offset it. So basically, both are dangerous for ‘in-house’ shootings, with the 5.56 having some additional risks for shoots near exterior walls. All guns are dangerous for the entire range of their flight, so always be mindful of what is behind your target. I used to suggest BB shot instead of OO buck for home defense for this very reason. ---
**Author:** ![Snarky\_Kong](https://avatars.discourse-cdn.com/v4/letter/s/a183cd/32.png) [@Snarky\_Kong](https://boards.straightdope.com/u/Snarky_Kong)\ **Post date:** [June 14, 2022, 3:15am UTC](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964/62 "2022-06-14T03:15:24Z")
> [@thelurkinghorror](#): > > Yes, other analyses have shown different, I’m repeating what may just be lore, but it’s a common argument Show them then? And didn’t the second half contradict the first? ---
**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\ **Post date:** [June 14, 2022, 6:17am UTC](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964/63 "2022-06-14T06:17:20Z")
[Here’s](https://www.outdoorhub.com/stories/2013/11/04/ar-15-appropriate-home-defense-part-one-penetration-issues/) a [couple](https://www.thearmorylife.com/5-56-vs-drywall-is-your-home-defense-gun-dangerous/) to [check](https://www.gun-tests.com/ammo/handgun-bullets-how-do-they-penetrate-in-home-materials-4/) out, I don’t know much about the general respectability of the websites but they seemed to be more free of BS that some of the other ones. Not necessarily scientific-rigor controlled, but thorough. Contradict what? ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [June 14, 2022, 8:05am UTC](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964/64 "2022-06-14T08:05:12Z")
And that’s why every single wall in my condo is made of concrete or cinderblocks. The fact that people willingly live in cardboard boxes has always baffled me. ---
**Author:** ![AK84](https://avatars.discourse-cdn.com/v4/letter/a/85e7bf/32.png) [@AK84](https://boards.straightdope.com/u/AK84)\ **Post date:** [June 14, 2022, 8:27am UTC](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964/65 "2022-06-14T08:27:48Z")
> [@RickJay](#): > > I’m not sure it would be true to say MOST people don’t know that. Hell, I don’t have any guns and I know that. Weren’t you in the Army? ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [June 14, 2022, 8:48am UTC](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964/66 "2022-06-14T08:48:46Z")
> [@AK84](#): > > Weren’t you in the Army? A military education is usually pretty narrow - you learn a lot about the things you use, some things about the things you _might_ use, and very little about the things you don’t use. ---
**Author:** ![Snarky\_Kong](https://avatars.discourse-cdn.com/v4/letter/s/a183cd/32.png) [@Snarky\_Kong](https://boards.straightdope.com/u/Snarky_Kong)\ **Post date:** [June 14, 2022, 11:10am UTC](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964/67 "2022-06-14T11:10:55Z")
You base your living decisions on how likely you’re going to be hit by stray rounds from your neighbor having a shootout? ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [June 14, 2022, 11:19am UTC](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964/68 "2022-06-14T11:19:10Z")
I tend to think more in terms of Scud missiles, actually. (I’m kidding, of course - it’s just that very little wooden or plaster construction exists in my country; I’m not sure building codes allow it. Besides, we have a lot more rocks than trees here). ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [June 14, 2022, 12:04pm UTC](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964/69 "2022-06-14T12:04:39Z")
I live in the US in a typical multi-story condominium / apartment building. All the structure is concrete, cinderblock, or steel. But … The interior walls in any one unit are sheetrock over wooden or metal studs. The walls between one unit and another are in some cases cinderblock, but are generally just wider wood/metal studs and double-layers or thicker sheetrock to provide adequate fire (as in flames, not guns) resistance. Floors / ceilings are poured concrete. Stray rounds from my neighbors on left or right could come through the walls easily. Not so much from my neighbors above or below. Fortunately shootouts are rare with this crowd. ---
**Author:** ![AK84](https://avatars.discourse-cdn.com/v4/letter/a/85e7bf/32.png) [@AK84](https://boards.straightdope.com/u/AK84)\ **Post date:** [June 14, 2022, 12:15pm UTC](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964/70 "2022-06-14T12:15:30Z")
> [@Alessan](#): > > And that’s why every single wall in my condo is made of concrete or cinderblocks. The fact that people willingly live in cardboard boxes has always baffled me Come on. Don’t you love knowing where everyone whenever they walk, sit down, take a deep breath… > [@Alessan](#): > > I’m kidding, of course - it’s just that very little wooden or plaster construction exists in my country; I’m not sure building codes allow it. Besides, we have a lot more rocks than trees here). Our changes from brick to wood as we go into the Himalayan foothills. I think cold climate is better handled by wood and a warm one by brick (I could be wrong). ---
**Author:** ![RickJay](https://avatars.discourse-cdn.com/v4/letter/r/bb73d2/32.png) [@RickJay](https://boards.straightdope.com/u/RickJay)\ **Post date:** [June 14, 2022, 1:09pm UTC](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964/71 "2022-06-14T13:09:34Z")
> [@AK84](#): > > Weren’t you in the Army? You’d be very surprised how little general firearms knowledge the Army teaches. Things like “What does caliber mean?” are basically not taught at all, unless perhaps you become a pretty high end commando or something. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [June 14, 2022, 3:51pm UTC](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964/72 "2022-06-14T15:51:02Z")
> [@Alessan](#): > > And that’s why every single wall in my condo is made of concrete or cinderblocks. The fact that people willingly live in cardboard boxes has always baffled me. Pshaw! Concrete and cinderblock might be okay against small caliber arms but you need to think bigger…as in 30mm. I have 2 meter thick steel reinforced earth berm and a double roof with reactive armor for ground penetrating missiles. Inside, I have an advanced air filtration system capable of detecting and removing biological, chemical, and radiological contaminants down to the 0.5 micron particle size and a 50,000 liter reservoir with UV sterilization. Steel frame Chobham doors with auto-targetting miniguns flanked with flamethrowers protect the main entrance, while the secret exit requires diving underwater and swimming through a pipe too narrow for scuba gear, requiring the ability to hold your breath for a minimum of 4 minutes. And that is only Level 1. > [@LSLGuy](#): > > I live in the US in a typical multi-story condominium / apartment building. > > All the structure is concrete, cinderblock, or steel. But … If you are in a “typical” condo or apartment building, nearly everything above the foundation or parking garage is wood-framed oriented strand board (OSB) sheating with a painted on adobe or brick/rock facade. That stuff won’t stop anything larger than a .22 LR unless it hits a stud. Stranger ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [June 14, 2022, 3:56pm UTC](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964/73 "2022-06-14T15:56:54Z")
Do you have sharks with frikkin’ lasers on their heads? ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [June 14, 2022, 4:07pm UTC](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964/74 "2022-06-14T16:07:48Z")
No, of course not. That would be ridiculous. Sharks are expensive to feed and a laser mounted on cartilage would not be stable, notwithstanding that they could not carry around a large enough battery pack/capacitor bank to power an effective weaponized laser. I did have wombats armed with HK MP7s but I found the 4.6x30mm to be ballistically ineffectual despite its ability to penetrate soft body armor, and the creatures had difficult maintaining an accurate sight picture despite the light recoil. I replaced them with VX gas and hydrofluoric acid, backed up by sonic alarms that will incapacitate invaders, which is easier to maintain and doesn’t require changing the litter. Stranger ---
**Author:** ![ParallelLines](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/parallellines/32/3575_2.png) [@ParallelLines](https://boards.straightdope.com/u/ParallelLines)\ **Post date:** [June 14, 2022, 4:12pm UTC](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964/75 "2022-06-14T16:12:12Z")
Actually, I’ve always been in awe of @Stranger_On_A_Train’s intellect, but his house description triggered some thoughts. I bet he’s living in [Eureka](https://en.wikipedia.org/wiki/Eureka_(American_TV_series))! Probably couldn’t get (or trust) a Smarthouse like Sara, but certainly could get another repurposed security shelter. Seriously though (since we are in FQ still) - he’s absolutely correct about the majority of modern apartment and/or condo construction. Expect any non-frangible round to pass through multiple walls unless we’re talking about birdshot or 22LR (and even then I’d worry about the other side of the immediate wall). Apartment living is what made me first buy the Glaser ammunition I mentioned upthread. Back to @Alessan’s comment - when I was in Jerusalem for a family event (literally during the 2014 Gaza-Israel conflict when Ben Gurion had only reopened the day before, our timing was either amazing or crappy depending on your POV) - the vast majority of the structures reminded me of the American Southwest - heavy, imposing thick walled structures designed to keep the killer heat out, with much conduit and cabling passed through to enable fully modern amenities. It was a culture/assumption clash compared to modern American build fast/cheap and hide everything behind sheetrock. I will not deny that the stupid part of me thought things like “And when the Zombie invasion a la World War Z happens, Max Brooks got it right, this is the place to be!” Still more FQ goodness though - almost every firearm round developed historically was built to be lethal, to game, or to humans, with the assumption that you needed range, to punch through hide / muscle / bone, and/or foliage. Never expect a non-hardened structure to be cover, it’s concealment (for better AND for worse) at best. ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [June 14, 2022, 4:12pm UTC](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964/76 "2022-06-14T16:12:24Z")
> [@Stranger\_On\_A\_Train](#): > > No, of course not. That would be ridiculous. Sharks are expensive to feed and a laser mounted on cartilage would not be stable, notwithstanding that they could not carry around a large enough battery pack/capacitor bank to power an effective weaponized laser. > > I did have wombats armed with HK MP7s but I found the 4.6x30mm to be ballistically ineffectual despite its ability to penetrate soft body armor, and the creatures had difficult maintaining an accurate sight picture despite the light recoil. I replaced them with VX gas and hydrofluoric acid, backed up by sonic alarms that will incapacitate invaders, which is easier to maintain and doesn’t require changing the litter. > > Stranger You must be one of those eco-warrior supervillans. Genetic engineering is ethical when done on non-sentient species. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [June 14, 2022, 4:18pm UTC](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964/77 "2022-06-14T16:18:37Z")
> [@Stranger\_On\_A\_Train](#): > > If you are in a “typical” condo or apartment building, nearly everything above the foundation or parking garage is wood-framed oriented strand board (OSB) sheating with a painted on adobe or brick/rock facade. That stuff won’t stop anything larger than a .22 LR unless it hits a stud. Sorry; I wasn’t explicit enough. Mine is “typical” for 10-20 story highrises which are a dime a dozen here along the SoFL coast. Think Champlain Towers but less collapsy. I agree 100% w your description of almost all 2-3 story walk-up apartments, condos, & “townhouses” nationwide built after ~1970. And of a sizeable fraction of the older housing stock too. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [June 14, 2022, 5:04pm UTC](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964/78 "2022-06-14T17:04:02Z")
> [@running\_coach](#): > > You must be one of those eco-warrior supervillans. Nah, being a supervillain takes way too much time and motivation, and Elon Musk aside it rarely goes well. Not really interested in villainy for its own sake; I mostly just want to be left alone with my reading and whiskey. Stranger ---
**Author:** ![mbh](https://avatars.discourse-cdn.com/v4/letter/m/a6a055/32.png) [@mbh](https://boards.straightdope.com/u/mbh)\ **Post date:** [June 14, 2022, 6:11pm UTC](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964/79 "2022-06-14T18:11:10Z")
> [@ParallelLines](#): > > the vast majority of the structures reminded me of the American Southwest - heavy, imposing thick walled structures designed to keep the killer heat out, with much conduit and cabling passed through to enable fully modern amenities. Our houses look impressive, but for anything built after World War II, it’s probably an illusion. My house looks like an adobe structure, but it’s just stucco over chicken wire. The structure itself is normal 2x4s and plywood. ---
**Author:** ![ParallelLines](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/parallellines/32/3575_2.png) [@ParallelLines](https://boards.straightdope.com/u/ParallelLines)\ **Post date:** [June 14, 2022, 6:14pm UTC](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964/80 "2022-06-14T18:14:36Z")
I grew up just outside of old Mesilla in Las Cruces NM. Yeah, you’re absolutely right about the original construction vs the modern Santa Fe style of all look, no substance to comply with the building codes. But that’s why I had to comment on the utilities - all the conduit and pass throughs to add in electricity, A/C, etc felt very familiar. Not that even the old structures of southern NM (correction, old European, the cliff dwellings are something else!) hold up to some of the old structures of Jerusalem. [Previous page](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964.md?page=3) [Next page](https://boards.straightdope.com/t/please-explain-bullet-sizes-for-guns-and-other-ammo-jargon/965964.md?page=5)