So I decided to build a spud gun. Yes I know, everybody's done it. Just not necessarily like this.

4" by 1'8" chamber funneled down to a 2" by 5' barrel
6'8" total length, and still has blue fire shooting out.  Muzzle flash ftw.
All piping is solid sore schedule 40 pvc, heavy duty cement.

and now,







 

nice tater cannon.

shot some spuds earlier.  This is one violent s.o.b.

I shot a plastic kiddy baseball bat with a six second hairspray charge.  BOOM!!  Almost ripped the cannon away from me!

Shiano:

5' of 2" pvc
9" of 4" pvc
4" x 4" x 2" coupler w/ 90 degree sweep
4" cleanout w/ threaded cap
2" cleanout w/ threaded cap
4" to 2" reducer
regular old bbq grill igniter
purple primer and heavy duty pvc cement

All pvc is schedule 40 solid core.

Drill the 2" cap out for the igniter. The 2" cleanout will be going into the sweep in the big coupler. Fold the wires up so the spark gap is about in the opening of the sweep in the inside of the pipe. Set the gap how you want, you'll be able to mess with it later too. Glue that igniter down into the 2" cap, and cement the cleanout to the coupler. I wrapped my ingiter in electrical tape as an intentional weak leak to avoid an explosion, instead of glue.   Go ahead and cement the 4" cleanout to whatever side of the big coupler you want to be the rear.  Cement the segment of 4" pipe to the big coupler, and then the reducer to the other side of that. Your chamber is done. Just put the barrel on and voila.  You can cut it off if you want, but you dont need to.  I left mine full length and still get blue flame out the end.  Also, the fumes from the primer and glue will blow up in you face...  They did in mine...

Ether will probably blow this thing sky high, hairspray is plenty.