combustion cannons (legality)?

flanum

hi, this is probably best suited for some other forum, but here goes!

just purely for the craic.. "a friend of mine" has recently built a few combustion cannons. basically what they are is giant spud-guns! they are made from pressure regulated lengths of pvc with various attachments etc, basically you shove a spud or some other projectile down the barrel and give the chamber a few squirts of hairspray/deoderant etc (anything with propane in it) and using a bbq igniter, it then fires the projectile some 300-400 yards with a bloody great bang!
now this is only for the craic, they would absolutely not be used for anything dodgy or harm etc, just basically targets and just firing off into the blue yonder etc!

actually a great use for them would be for training gun dogs!!

basically i was just curious as to know would they be considered a firearm or what constitues a firearm in this country?

for reference you can see "a freind"of "afriend" firing one here : http://www.youtube.com/watch?v=3D9V72uTSkU

and if you search in youtube for spudgun or spud gun, you will see its actually quite huge in the states.

spuds away.

Sparks

If the projectile leaves the barrel with more than one joule of kinetic energy, then it's a firearm, legally speaking.

flanum

ah.. erm.. any idea where i could get a chrono that would accomodate a projectile with diam 40mm?

dresden8

This geezer has been watching brainiac.

Sparks

No, but you don't really need one...

Get your kinetic energy - your average spud is 100 grams or so, and it has to be 1 joule at most, so your velocity is going to be a maximum of 4.47 m/s. Feed that into the range equation and you get a maximum range of 2.04 metres, for the mathematically ideal potato.

In other words, fire a spud from that thing and if it goes over 2 metres, you can be pretty sure you're breaking firearms law and could be done for it if you annoyed anyone enough. And there are more than enough easily-annoyed people in today's world to get you in trouble...

expressway

"Videotaping this crime spree was the best idea ever!"

bullets

Makes me wonder you might get more than 1J of energy out of a Pea shooter
and a hefty set of lungs. I can see the headlines now....
Man arrested and found in possession of a pea shooter!


~B

Victor

bullets wrote: »

Makes me wonder you might get more than 1J of energy out of a Pea shooter and a hefty set of lungs. I can see the headlines now.... Man arrested and found in possession of a pea shooter!

Taking a 1g pea (thats a biggish pea), you would be talking about a situation of a pea capable of going 206m - rather implauseable

Sparks

flanum wrote: »

actually a great use for them would be for training gun dogs!!

I missed this the first read through, but I have to say - I doubt the ISPCA would support the idea of stuffing dogs into lengths of PVC, and I really think that this isn't the best way to teach a dog to fly.

flanum

s'pose your right, but its a great starch accelerator all the same!