SpudFiles

-RED: Seal

-GREEN: Firing pin

-BLACK: Projectile

The bullet seals the barrel. Air can't get behind the bullet and push it down the barrel. When something hits the firing pin it moves the bullet a little bit forward, but enough to the pressurized air get behind the bullet and shoot. :bounce:

The design works well but manufacturing the projectiles takes lots of effort for single use. An alternate design shoots a similar designed valve core to the rear for re-use, while permitting much larger selection of projectiles. Look in my sig for examples.

If the the effort can lead to good results then why not try?

The design certainly has it's benefits - one of the most notable will be consistency.

A professor was leading a project for Engineering seniors in my school - and I asked them why they picked a similar design for testing - repeatability was their claim. They were designing a kinetic energy delivery system to imitate concrete debris being blasted from a wall at a soldier behind it - the end product being used for the testing and qualification of body armor.

It makes sense - given that the projectiles mass can be fine tuned easily - and the seals will always be in the same condition: "new". Therefore, give chamber pressure and temperature you should be able to depend upon a consistent muzzle energy.

Typically, someone already patented it: http://www.spudfiles.com/spud-cannon-re ... ss#p146694