T CUPS YOU ASKED ?

[melloroadman]

After all this info gathering what are you going to do ? The answer is . I replaced the striker weight today and for now I am going to do the 2200 psi fill that yielded these results  . Marvin
http://www.gatewaytoairguns.com/airguns/forums/thread-view.asp?tid=11953&posts=6&highlight=condor%20day%202&highlightmode=1#M93570

[TCups]

So having found the power curve with the broadest sweet spot, you know your optimum fill pressure.  But, unless you hand pump, how do you know you are filling to exactly 2200 PSI?  If I fill either my AA 410 ERB or BSA Scorpion from the scuba tank, the final fill pressure is what ever the equilibrium pressure is after the full fill.  I am filling to about 200 - 210 BAR (3200 - 3300 PSI) off a full fill on the tank, and once the partially used tank drops the fill pressure to something like 150 - 175 BAR, I have the scuba tank topped off again.  I guess you would have to have an in-line regulator to be able to fill PCP's to a constant fill pressure with a scuba tank or carbon fiber tank.  

And if you over fill a PCP's tube to a higher than optimum pressure, at some point, after a number of shots, the pressure is going to drop to the optimum range anyhow, so I will always be shooting most of the shots somewhere in the optimum power curve range, even with an overfill, right?  Or am I missing something?  One more question.  If turning down the power setting on the AA 410 lowers the pressure of the firing cycle (which as I understand it is not the same as a regulated PCP, couldn't you just, in effect, back the power down until you find the setting where the air rifle performs best, presuming that at any power setting less than full power, the overfill would make even less difference?  

Please understand, this is in no way a critique of the extensive testing you have done on fill pressures, etc.  I am just so new to shooting PCP's that I am not sure what it all means and whether I need to be more careful of my fill pressures and shot counts.

[melloroadman]

Tommy I have a inline pressure gauge coming off my tank I crack the valve on the tank slowly until the pressure I desire is reached in the rifle and then turn the valve off . That is how most people do it . If you fill the rifle to too high of a psi you can lock the exhaust valve and the rifle will not fire . That is why the fps drop off when psi is to high . The psi in the tank is so high the valve will not open when the striker hits it . It is a balancing act between spring pressure and air pressure that opens and closes the valve . The sweet spot is were the valve stays open its longest to allow the most air to flow . I have never owned a A.A. rifle Tommy and never looked at its internal parts so the question you ask about it I hesitate to answer . If your shot deviation gets to wide you are going to have poi shift that will be un acceptable to you so you want to stay with in the curve that will yield a good shot count and fps with exceptable poi shift . Marvin
http://www.stealthresource.org/valve.htm
This is not what is in your rifle but it gives a good discription as to what is going on .

[SAVAGESAM]

Tcups I don't know what kind of filling set up you or Marvin has, but I have the A.F. standard scuba clamp with a gauge. As long as you have a scuba tank that has more psi than what you like in your gun tank, your good to go. Example, My scuba tank holds 3000 Psi. I fill my gun tank to 2500 Psi. by the gauge and shoot down to around 1800. I get a decent number of  fills this way before my scuba tank "equalizes" at 2500 Psi.