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Carl Quick's LiteWieght 2240

So for about the last 24 months, I've had her on a serious diet. Now I am happy to report that she lost nearly 13 ounces and is feeling so much better. And let me say one thing, when I pick her up with one hand now she is light as a feather. Well, almost a feather.

Things I have done so far:

OEM main tube was lightened by me.
Barrel is OEM and trimmed down by me.
Main tube plug is made of Delrin by me.
Gas cap is aluminum, comes from HPA and bored out by me.
Hammer is made from Delrin by me with a modified 1701P striker.
Valve is an aluminum Disco rear end with a brass Pro-Top by Anthony.
Trigger grip frame is aluminum by Bluefork Design and then hogged out by Gregg.
Front barrel band is aluminum, made by Anthony, drilled by Rich and milled by me.

Quickster47



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Well, a couple of things.

July 5 2012 at 2:44 PM

Steve in NC  (Login pneuguy)
Troll, Banned User or Assorted Delinquent
from IP address 74.242.231.138


Response to Question about the "Valve Ineffectiveness Chart"....

1. The basic idea behind "Sonic Horizon" was, due to the fundamental limit imposed by the speed of sound on the speed of propagation of pressure change, it makes no difference to the acceleration of the pellet whether the valve closes or remains open after the pellet crosses the "Horizon," because the pressure change created by the valve closing (or not) can't reach the pellet before it departs from the muzzle. In other words, the only gas that can contribute to accelerating the pellet in the example MV = 850fps case, is the gas occupying the first 33% of the bore. That is to say, 33% of the volume of the bore.

2. When air expands in an airgun, the expansion is so rapid that no significant heat has time to transfer from the walls of the bore etc. to the air. That is to say, the expansion is (to a good approximation) adiabatic. Under that condition, pressure isn't inversely proportional to volume, but (because air is effectively a diatomic gas) to volume raised to the 1.4 power. Therefore, for example, doubling volume wouldn't reduce pressure by factor of 2, but by 21.4 = 2.64.

Steve

 
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