METAL SPUD GUN - 3 ASSORTED / ONLY 1 SUPPLIED
About this deal
Any combustion cannon with a potential muzzle energy of greater than 1 ft-lb (it may be 1 Joule, I forget) will fit into one of these groups.
Threaded Fittings: commonly available in BSP or NPT (not interchangeable) they generally require a fitting attached to a pipe by other means to allow screwing into another threaded fitting. The exception to this is steel pipe, the ends of which can have the appropriate thread cut into them. It is rare for a spud gun to be powerful enough to break the sound barrier, although there are some cases of this happening using specialized designs. The spud guns used are typically hybrids; but some pneumatic cannons have achieved the feat, either by using a special low-density gas, such as helium,  or high pressures combined with a fast valve.  There is also one reported case of a combustion design achieving super-sonic velocities. 
Another reason I asked is because I've seen the people who host 'Brainiac' on Sky One fire a potato cannon in a huge field (which was completely empty, though houses WERE indeed nearby). It is also illegal to discharge any firearm within a certain (not many feet) distance from the highway. Just make sure nobody spots you and fire the cannon on your or a friends piece of land, between trees and far away from other homes if possible.
New stuff". The Spudgun Technology Center. 14 January 2010 [6 July 2002] . Retrieved 16 August 2011. Wise, Roger (2003-10-29). "Solvent welding of thermoplastics". TWI. Archived from the original on 2008-02-12 . Retrieved 2009-06-01.These blue soft darts can be used with all soft dart guns. You will receive 30 x Blue Soft Darts...
Duct tape: sometimes used in simple cannons, it is unsuitable for sealing any significant pneumatic pressure and if used on a combustion cannon the heat produced can soften the adhesive and melt the tape, greatly weakening any seal or joint it creates. Promotional sports cannons: Portable pneumatic cannons which run on bottled CO 2 are common at large sports games in the U.S. where they are used to project items such as T-shirts or wrapped food into the audience. Such cannons can be dangerous: the Phillie Phanatic injured a fan with a hot dog cannon in June 2018.  Such "air cannons", as they are often called, tend to be made of higher-quality materials than an average pneumatic spudgun, but they use the same methods of operation.
Spud Guns & Dart Guns
Your open field and tree belong to someone and probably have public access. This means that in spite of your best efforts someone will inevitably be injured. You must be very young or daft not to consider the consequencies of firing your gun in any circumstances as described. At the very least, one day the tube will weaken, rupture and discharge its contents in your direction. A potato cannon is NOT considered a Firearm in the US, but it IS considered one here?I know, Gun Laws in the US are much, much less strict than they are here in the UK, and fair enough if governments have different considerations - but if a Potato Cannon is NOT considered a Firearm in the US, WHY is it in the UK? Alternate designs have also been used which use a sharp projectile to puncture the burst disk, like a mortar  or using a manual puncturing device to trigger failure of the disk.  These allow total control over burst disk cannons without the need for hybrid technology and materials as simple as plastic tape can be used for the disk. Burst disk cannons have also been made which are fired electrically, using a nichrome wire to trigger failure by heating.  Connections [ edit ] Welding, soldering and gluing [ edit ]