Yup a 35 pound kid...

Can not inflate a tire to 40 PSIG without mechanical advantage! When I was young we had two mechanical pumps, one a straight cylinder leather piston one and another "foot" pump with a step on it. I do recall the foot operated one was much easier to use as it worked off of a lever system.

This is a very interesting topic as it seems we are getting at the heart of how springers work (or don't).

Basic hydraulic theory says if you use a small piston to pump up a larger one you can increase the force, and I can not see how a large piston driving a small one could result in higher force. What seems to be going on is we are taking a large volume of air and forcing it into a smaller volume and forcing out a lower mass piston (the pellet) and doing so increasing the velocity in the barrel. As mentioned by Carlos in a previous reply we are probably not looking at laminar flow of gasses but it may be advantageous to try for that ideal.

So what is going on here? We have a 4.7 cubic inch cylinder emptying into a 1.6 cubic inch area(barrel .22x 7" long) About a 3:1 ratio, dang it's been too many years since I studied laminar and turbulant flow and I almost can't see why the breach end of the port should not be just a hair less than .177 or .22, instinctivly I would think that would provide laminar flow. I am thinking a large port on the cylinder side tapering into a venturi and then out to the intended target?

Paul, I have to say you have a feel for this, "The energy required to launch the pellet to its target comes from the main spring. It must" as where else can any energy come from unlesss there is detonation of oil in the cylinder/chamber? With any detonation would come some variables that would preclude any repeatable result?

Kristin