# What's the most potent automatic weapon a person can carry? **URL:** \ **Category:** Factual Questions\ **Created:** [January 20, 2006, 3:20am UTC](https://boards.straightdope.com/t/whats-the-most-potent-automatic-weapon-a-person-can-carry/340776 "2006-01-20T03:20:32Z")\ **Posts on this page:** 8\ **Page:** 4
**Author:** ![mks57](https://avatars.discourse-cdn.com/v4/letter/m/b9bd4f/32.png) [@mks57](https://boards.straightdope.com/u/mks57)\ **Post date:** [January 21, 2006, 9:07pm UTC](https://boards.straightdope.com/t/whats-the-most-potent-automatic-weapon-a-person-can-carry/340776/61 "2006-01-21T21:07:40Z")
> [@633squadron](#): > > Whew! For a moment, I was afraid I’d have to explain it. I mean geez, doesn’t a blast radius of 500 yards and a _range_ of 100 make you just a _bit_ suspicious? :rolleyes: Not necessarily. I remember being told something similar in grenade training about the WP grenade. Its effective range was larger than the distance it could be thrown by the average soldier. ---
**Author:** ![Ranchoth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ranchoth/32/1066_2.png) [@Ranchoth](https://boards.straightdope.com/u/Ranchoth)\ **Post date:** [January 22, 2006, 1:35am UTC](https://boards.straightdope.com/t/whats-the-most-potent-automatic-weapon-a-person-can-carry/340776/62 "2006-01-22T01:35:04Z")
You know, actually, I seem to remember that one could, theoretically, build a bullet-sized nuclear warhead using Americium isotope “fuel” that’d have a yield in the tens of tons. The catch being that, as I remember, said isotopes are hard to synthesize, and they have a half-life of like two days. Kinda impractical, any way you go at it. ---
**Author:** ![Raguleader](https://avatars.discourse-cdn.com/v4/letter/r/258eb7/32.png) [@Raguleader](https://boards.straightdope.com/u/Raguleader)\ **Post date:** [January 22, 2006, 6:36am UTC](https://boards.straightdope.com/t/whats-the-most-potent-automatic-weapon-a-person-can-carry/340776/63 "2006-01-22T06:36:40Z")
> [@633squadron](#): > > Whew! For a moment, I was afraid I’d have to explain it. I mean geez, doesn’t a blast radius of 500 yards and a _range_ of 100 make you just a _bit_ suspicious? :rolleyes: I dunno, it’s the Army. 😃 One professor of mine mentioned a couple of interesting nuclear weapons the Army played with, including a cannon that fired nuclear shells and was capable of hitting a target as close as 100 yards away (it’s maximum range was a bit farther than that, I think). IIRC, another idea involved a nuclear landmine which infantry would deploy in the face of a Soviet tank offensive. Run out in the path of the tanks with the mine in a backpack, drop the pack into a pre-placed concrete hole, run back to cover before the tanks catch up with the mine. 😃 ---
**Author:** ![Ranchoth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ranchoth/32/1066_2.png) [@Ranchoth](https://boards.straightdope.com/u/Ranchoth)\ **Post date:** [January 22, 2006, 7:51am UTC](https://boards.straightdope.com/t/whats-the-most-potent-automatic-weapon-a-person-can-carry/340776/64 "2006-01-22T07:51:11Z")
> [@Raguleader](#): > > IIRC, another idea involved a nuclear landmine which infantry would deploy in the face of a Soviet tank offensive. Run out in the path of the tanks with the mine in a backpack, drop the pack into a pre-placed concrete hole, run back to cover before the tanks catch up with the mine. 😃 Might have been the [Special Atomic Demolition Munition](http://en.wikipedia.org/wiki/Special_Atomic_Demolition_Munition)? ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [January 22, 2006, 5:34pm UTC](https://boards.straightdope.com/t/whats-the-most-potent-automatic-weapon-a-person-can-carry/340776/65 "2006-01-22T17:34:28Z")
> [@Ranchoth](#): > > You know, actually, I seem to remember that one could, theoretically, build a bullet-sized nuclear warhead using Americium isotope “fuel” that’d have a yield in the tens of tons. The catch being that, as I remember, said isotopes are hard to synthesize, and they have a half-life of like two days. Kinda impractical, any way you go at it. According to [this](http://en.wikipedia.org/wiki/Critical_mass) you’d still need something like 9kg for a critical mass of americium. Looking at the list californium-251 looks like the best bet with a 5kg critical mass (although on another page they suggest 2kg might just do it). With an 898 year half life it’ll hang around longer but it seems it is a very lethal substance bomb or no bomb. Might be a bit too nasty to carry around as a nuclear “bullet”. ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [January 22, 2006, 5:39pm UTC](https://boards.straightdope.com/t/whats-the-most-potent-automatic-weapon-a-person-can-carry/340776/66 "2006-01-22T17:39:33Z")
Forgot to add Americium-242 (probably what you would use for a bomb) has a 141 year half life. Actually I am not sure I fully understand the deal with Americium since most of the isotopes have less than a 51 hour half-life but 242 is a nuclear isomer (or meta state?) that has the 141 year half life. Sorry for the hijack…just some weirdness I had not encountered before. ---
**Author:** ![Ranchoth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ranchoth/32/1066_2.png) [@Ranchoth](https://boards.straightdope.com/u/Ranchoth)\ **Post date:** [January 23, 2006, 4:00am UTC](https://boards.straightdope.com/t/whats-the-most-potent-automatic-weapon-a-person-can-carry/340776/67 "2006-01-23T04:00:04Z")
> [@Whack-a-Mole](#): > > According to [this](http://en.wikipedia.org/wiki/Critical_mass) you’d still need something like 9kg for a critical mass of americium. Looking at the list californium-251 looks like the best bet with a 5kg critical mass (although on another page they suggest 2kg might just do it). Just out of curiosity, how much physical space would those 9kg and 2kg masses take up? ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [January 23, 2006, 3:59pm UTC](https://boards.straightdope.com/t/whats-the-most-potent-automatic-weapon-a-person-can-carry/340776/68 "2006-01-23T15:59:29Z")
These small nukes seem perfect for throwing down a cliff or a shaft - anywhere where there’s plenty of good solid stuff between you and it when it goes off. [Previous page](https://boards.straightdope.com/t/whats-the-most-potent-automatic-weapon-a-person-can-carry/340776.md?page=3)