Originaly posted by spudlover,Right after I posted my first message I cut down the barrel so only 3.5" was sticking in the chamber. This yielded an average increase of 30fps in velocity over 8 shots! I wonder what effects of having a long barrel in the chamber are. Do they disrupt the "funneling" of the air? Here are a few pics of my test setup.
My L3, brand new and not finished. Note the aluminum box containing the stun gun and fan controls. Latke, have you had problems with fan drain. I started out with 18volts, at the end of the day it was 15! Working on an AC/DC adapter.

My dad getting ready to shoot. Note the wood box, we set the end of the barrel on it. The first chrono sensor is approximately 1ft from the muzzle. Only problem was small potato bits flying on it.

This was the the "penetration" layer, over 5 layers of heavy duty carboard easily pierced every shot. The tennis balls and more powerful shots penetrated all 5 layers, went through 3 feet of paper wadding and came out the back hard enough to split the plywood on our garage door. This photo was taken after several shots.

The launcher with a 4ft long TB barrel. Tennis Balls fell so much more powerful than spuds, and they are much louder.

Pic of my "CCU," the wiring has since been cleaned up. I have also removed the stun gun circuit board.

And finally a pic of my cut down pass through barrel. One of my most highly reccomended upgrades. The ease of loading a spud compared to muzzle loading is unbelieveable.

That was a lot. My test conclusions. Don't have your barrel extend more than 3" into the chamber, or you are asking for trouble. BTW, how did the 2.5" CB test go Latke?