Originally Posted by Rusty Lugnuts
great explanation, so how do upgrade valves work? maybe different springs or orifices or something else?
a stronger spring that requires more force to close it, and the way the valve is shaped to redirect the gas flow in either direction. take a look at the NPAS on a WE, by adjusting it forward you get less fps, because more gas is directed to the rear. by adjusting it to the rear, it allows more gas directed into the chamber.
Originally Posted by voorhees -FWA-
but my point is, the same amount of gas is expelled out of the mag regardless of there being a BB or not... How does the hammer and the mag know there's a BB in there... don't care what happens to the gas after the striker valve is hit as you said, "dry fire on a gas gun uses less gas." That's what's not making any sense to me... you and Jeff gave me an explanation on what happens after the valve is hit by the hammer...
Meh, whatever... OP use less BB's and see what happens; instead of 40, try 20...
The way that the valve works is pretty smart. The valve they're talking about is in the chamber, not the mag. its used directionally to split the gas entering the nozzle for two functions, to propel the bb and to activate the blowback mechanism. The valve moves back and forth, due to pressure. When there is a bb still in the barrel, the pressure of the gas behind it keeps the valve balanced and counteracting the force of the rest of the gas behind it trying to force it closed. Once the BB leaves it though, the pressure is interrupted, and closes the valve, starting the blowback mechanism.
so if you dry fire, there is no bb to keep the pressure in the barrel, and while some of the initial gas is vented through, the valve closes much quicker with no bb's than it does with a bb in the chamber, therefore using less gas.