# Is it illegal to build a large working cannon? **URL:** \ **Category:** Factual Questions\ **Created:** [May 18, 2009, 3:51am UTC](https://boards.straightdope.com/t/is-it-illegal-to-build-a-large-working-cannon/496817 "2009-05-18T03:51:10Z")\ **Posts on this page:** 18\ **Page:** 1
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [May 18, 2009, 3:51am UTC](https://boards.straightdope.com/t/is-it-illegal-to-build-a-large-working-cannon/496817/1 "2009-05-18T03:51:10Z")
If you had mad design and machining skillz would it be legal to construct a large bore working cannon or Gatling gun style artillery piece for your own amusement, or do laws limits even weapons you build yourself? ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [May 18, 2009, 3:54am UTC](https://boards.straightdope.com/t/is-it-illegal-to-build-a-large-working-cannon/496817/2 "2009-05-18T03:54:18Z")
You can buy full-size muzzle-loading cannon barrels through the mail. By ‘full size’ they mean exterior dimensions. I know that a replica Civil War field cannon barrel has a bore of about 3-1/3". ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [May 18, 2009, 4:09am UTC](https://boards.straightdope.com/t/is-it-illegal-to-build-a-large-working-cannon/496817/3 "2009-05-18T04:09:11Z")
[How to Build a 12 pound Mountain Howitzer Cannon](http://www.buckstix.com/HowitzerBarrel.htm) [Barrel Price List at Steen Cannons](http://www.steencannons.com/Barrel%20Price%20List.htm) I’m not seeing anything about licenses, or going to jail. ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [May 18, 2009, 4:14am UTC](https://boards.straightdope.com/t/is-it-illegal-to-build-a-large-working-cannon/496817/4 "2009-05-18T04:14:07Z")
With a muzzle-loader I think you’re safe. I am posting this without a cite, but I think there is a .55 or .60 caliber limit if you want to build something that fires fixed ammunition. (i.e., case, projectile, powder and primer all together.) What about a Naval gun, where a projectile is loaded from the breech and the powder charge is inserted behind it? I’ve got no answer. ---
**Author:** ![usedtobe](https://avatars.discourse-cdn.com/v4/letter/u/ec9cab/32.png) [@usedtobe](https://boards.straightdope.com/u/usedtobe)\ **Post date:** [May 18, 2009, 6:12am UTC](https://boards.straightdope.com/t/is-it-illegal-to-build-a-large-working-cannon/496817/5 "2009-05-18T06:12:51Z")
> [@Squink](#): > > [How to Build a 12 pound Mountain Howitzer Cannon](http://www.buckstix.com/HowitzerBarrel.htm) > > [Barrel Price List at Steen Cannons](http://www.steencannons.com/Barrel%20Price%20List.htm) > > I’m not seeing anything about licenses, or going to jail. What?! No trailer hitches? What kind of… ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [May 18, 2009, 6:21am UTC](https://boards.straightdope.com/t/is-it-illegal-to-build-a-large-working-cannon/496817/6 "2009-05-18T06:21:35Z")
They did it on _MythBusters_, and that show always says something about how you should try this stuff at home. So go for it. ---
**Author:** ![Johnny\_Q](https://avatars.discourse-cdn.com/v4/letter/j/898d66/32.png) [@Johnny\_Q](https://boards.straightdope.com/u/Johnny_Q)\ **Post date:** [May 18, 2009, 6:48am UTC](https://boards.straightdope.com/t/is-it-illegal-to-build-a-large-working-cannon/496817/7 "2009-05-18T06:48:44Z")
Second Amendment, no? ---
**Author:** ![Miscue](https://avatars.discourse-cdn.com/v4/letter/m/8491ac/32.png) [@Miscue](https://boards.straightdope.com/u/Miscue)\ **Post date:** [May 18, 2009, 11:00am UTC](https://boards.straightdope.com/t/is-it-illegal-to-build-a-large-working-cannon/496817/8 "2009-05-18T11:00:27Z")
**Is it illegal to build a large cannon?** Maybe, maybe not? **Is it illegal to build a large _working_ cannon?** How do you legally find out it _works_? 🙂 ---
**Author:** ![PatriotGrrrl](https://avatars.discourse-cdn.com/v4/letter/p/9dc877/32.png) [@PatriotGrrrl](https://boards.straightdope.com/u/PatriotGrrrl)\ **Post date:** [May 18, 2009, 11:41am UTC](https://boards.straightdope.com/t/is-it-illegal-to-build-a-large-working-cannon/496817/9 "2009-05-18T11:41:50Z")
> [@Miscue](#): > > How do you legally find out it _works_? 🙂 As long as you are allowed to posses it, and are at a location where you are allowed to fire regular firearms, you should be allowed to fire it. ---
**Author:** ![Scumpup](https://avatars.discourse-cdn.com/v4/letter/s/ce73a5/32.png) [@Scumpup](https://boards.straightdope.com/u/Scumpup)\ **Post date:** [May 18, 2009, 11:56am UTC](https://boards.straightdope.com/t/is-it-illegal-to-build-a-large-working-cannon/496817/10 "2009-05-18T11:56:37Z")
Muzzleloading cannons are unrestricted, as is the rule for muzzleloading weapons generally. Breechloaders over .50 caliber are classed as [destructive devices](http://en.wikipedia.org/wiki/Destructive_device). ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [May 18, 2009, 2:13pm UTC](https://boards.straightdope.com/t/is-it-illegal-to-build-a-large-working-cannon/496817/11 "2009-05-18T14:13:00Z")
Thanks for looking that up. I didn’t know .50 caliber was the limit, and thought it was slightly larger. ---
**Author:** ![Elendil\_s\_Heir](https://avatars.discourse-cdn.com/v4/letter/e/7cd45c/32.png) [@Elendil\_s\_Heir](https://boards.straightdope.com/u/Elendil_s_Heir)\ **Post date:** [May 18, 2009, 2:18pm UTC](https://boards.straightdope.com/t/is-it-illegal-to-build-a-large-working-cannon/496817/12 "2009-05-18T14:18:33Z")
A neighbor of mine once had a small brass cannon with which he would fire salutes on Independence Day. All the neighborhood kids loved it. Don’t think he ever got ticketed for either possession of a banned weapon or disturbing the peace. ---
**Author:** ![Cagey\_Drifter](https://avatars.discourse-cdn.com/v4/letter/c/b2d939/32.png) [@Cagey\_Drifter](https://boards.straightdope.com/u/Cagey_Drifter)\ **Post date:** [May 18, 2009, 2:37pm UTC](https://boards.straightdope.com/t/is-it-illegal-to-build-a-large-working-cannon/496817/13 "2009-05-18T14:37:05Z")
> [@Elendil\_s\_Heir](#): > > A neighbor of mine once had a small brass cannon with which he would fire salutes on Independence Day. All the neighborhood kids loved it. Don’t think he ever got ticketed for either possession of a banned weapon or disturbing the peace. How come the guy with the biggest/most weapons is always the most patriotic? ---
**Author:** ![Projammer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/projammer/32/559_2.png) [@Projammer](https://boards.straightdope.com/u/Projammer)\ **Post date:** [May 18, 2009, 3:05pm UTC](https://boards.straightdope.com/t/is-it-illegal-to-build-a-large-working-cannon/496817/14 "2009-05-18T15:05:25Z")
Gatling guns are also not restricted as they aren’t technically a full auto firing weapon. Full auto being defined by the BATF as multiple shots fired with a single trigger pull. [Gatling conversion for Ruger 22 rifles.](http://www.tacticalinc.com/ruger-1022-gatling-machined-aluminum-p-571.html) A crank and cam mechanism that operates the triggers. I saw one online once with the conventional circular design that people associate with Gatling guns. Don’t have time to find it again now. ---
**Author:** ![sqweels](https://avatars.discourse-cdn.com/v4/letter/s/f19dbf/32.png) [@sqweels](https://boards.straightdope.com/u/sqweels)\ **Post date:** [May 18, 2009, 3:30pm UTC](https://boards.straightdope.com/t/is-it-illegal-to-build-a-large-working-cannon/496817/15 "2009-05-18T15:30:56Z")
> [@Cagey\_Drifter](#): > > How come the guy with the biggest/most weapons is always the most patriotic? Because patriotism is defined as how much into war and military stuff you are. ---
**Author:** ![PatriotGrrrl](https://avatars.discourse-cdn.com/v4/letter/p/9dc877/32.png) [@PatriotGrrrl](https://boards.straightdope.com/u/PatriotGrrrl)\ **Post date:** [May 18, 2009, 3:44pm UTC](https://boards.straightdope.com/t/is-it-illegal-to-build-a-large-working-cannon/496817/16 "2009-05-18T15:44:08Z")
Note that that’s mechanical gatling guns (driven by a hand crank or such) not electric ones, which would be considered full auto. A friend of mine used to have one of those 10/22 kits. It was fun although it was hard to get both guns sighted in to the same spot. ---
**Author:** ![Ronald\_C.Semone](https://avatars.discourse-cdn.com/v4/letter/r/cc9497/32.png) [@Ronald\_C.Semone](https://boards.straightdope.com/u/Ronald_C.Semone)\ **Post date:** [May 18, 2009, 4:11pm UTC](https://boards.straightdope.com/t/is-it-illegal-to-build-a-large-working-cannon/496817/17 "2009-05-18T16:11:03Z")
> [@astro](#): > > If you had mad design and machining skillz would it be legal to construct a large bore working cannon or Gatling gun style artillery piece for your own amusement, or do laws limits even weapons you build yourself? I hate to keep bringing this up whenever a question such as this is posted, but it all depends on what country you live in and, if you live in the United States, probably what state you live. ---
**Author:** ![Kevbo](https://avatars.discourse-cdn.com/v4/letter/k/e47774/32.png) [@Kevbo](https://boards.straightdope.com/u/Kevbo)\ **Post date:** [May 18, 2009, 4:47pm UTC](https://boards.straightdope.com/t/is-it-illegal-to-build-a-large-working-cannon/496817/18 "2009-05-18T16:47:00Z")
I don’t have access to most of these from here, but the OP may find these google results interesting: [http://www.google.com/search?client=opera&rls=en&q=Bowling+ball+cannon&sourceid=opera&ie=utf-8&oe=utf-8](http://www.google.com/search?client=opera&rls=en&q=Bowling+ball+cannon&sourceid=opera&ie=utf-8&oe=utf-8)