The parts arrived the week after Christmas and I spent the next three weeks building it.
Heres some pictures of it now (click for full size):
Breech closed, open and loading.
Makes a very nice vapour plume.
The control section. You can see the blowgun trigger, the presta fill valve (innards removed), the check valve and the safety ball valve. Oh and the nice neatly glued chamber end.
You might be surprised to know the barrel tees are not fixed. Its because its impossible to align them perfectly and because the torque put on them when replacing a 1m barrel can easily distort them if they're secured at the base. The barrel is clamped in place by the compression fitting securely enough to lift the cannon with it.
Details:
Chamber = 60cm of 22mm copper pipe
Barrel = 100cm of 15mm copper pipe
C:B ratio = 1.36:1
Pressure = 240psi
Range with potatos = 300m+
Range with specialised ammo = 450m+
Valve is a 1/2" QEV actuated by a severely customised blowgun embedded in and venting through the semi-hollow grip (you can see the exhaust hole in the base of the grip)
If you'd like to find out more about its background theres a heap of my design posts including a pile of all the changes and original designs that I went through before finishing at this at the UKSGC forum.
Keywords: copper rifle bullpup cannon air spud gun spudgun polymorph
... well like yours
