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Spud Cannon Size

Posted: Sat Jun 21, 2008 10:44 pm
by cfrehr
I just made a potato gun using 2 feet of 4" pvc, 1 foot of 3" pvc and 1 foot of 2" pvc as the potato barrel. My cannon does not work well at all. Is the 2" barrel too short? im confused as to why my Big spud gun (4 feet) works worse than my Little spud gun (2.5 feet).....any answers?

Posted: Sat Jun 21, 2008 10:50 pm
by MrCrowley
C:B ratio.


Your barrel is far too short. It should probably be 10-15' with a chamber that size. A 1' 4" chamber and a 5' or 6' barrel will be decent enough.

Posted: Sat Jun 21, 2008 10:57 pm
by Lentamentalisk
your barrel is only 1 foot long. given your chamber size, you should make it about 10 feet long, for maximum velocity.

The ideal chamber to barrel ratio (C:B) is approximately 1:1, in volume. Though people will argue over that number, it varies largely with projectile weight, and other such factors.