About the factory regulator, I can't think of any fundamental reason it would work differently for .22 cal vs. .177 cal. It just seems to be very nonlinear. The bigger the difference between the setpoint and the cylinder pressure, the more variation there is. So in other words, a higher setpoint will give better consistency. Mine is behaving nicely after I burnished the valve seat and adjusted the setpoint to around 1500psi. In .177 cal, that produces 13fpe without any changes to porting. I had intended to tune it to 8 or 9fpe but when I backed down the setpoint, the results were not satisfactory so I just enjoy it at the higher power level. Granted, if it were fitted with a shoulder stock, I would have different aspirations for it because I would want to stretch it out to longer distances. For that, I suspect the factory reg would be inadequate. But as it stands, it will put a variety of different pellets into a dime at 25 yards when rested and that exceeds my expectations for an air pistol. BTW, this nonlinearity is a function of the forces acting to close the valve and those acting to open it. That part's pretty obvious, right? Well, the force acting to close the valve is simply the output pressure...ideally, that stays the same. However the force acting to open it is a combination of the Belleville stack and the cylinder pressure. So as the cylinder pressure changes, so does the force. The way to minimize the effect is to make the valve aperture very small. That way the cylinder pressure acts upon a very small area and only represents a small fraction of the Belleville force. The competing issue is that a tiny aperture affects recovery rate and that's why makers of paintball regulators walk a fine line to balance the two. But it's not really a concern for a single-shot pellet pistol like this so I suspect SPA could have done a better job here. I kinda eyeballed the reg when I had it apart to see if there was an easy way to address it but it wasn't obvious. If any of you smart fellas have an idea, I'd love to hear it.
Greg, the valve (silver cap behind the transfer block) has 2 o-rings-one on either side of the port in the transfer block. These are designed to seal that area to prevent air loss there but the design has its issues. The block rotates around the diameter of these o-rings when opened and closed. On mine, most of the air leakage seemed to be coming from the o-ring area between the transfer block and the barrel. A little baby powder ligthly applied to the area may help you seek where the air is coming from when fired.
Greg, the o-rings sit in grooves in the silver valve and are covered up by the transfer block when the valve is screwed in. You are not able to see them unless you unscrew and remove the valve from the pistol and then the transfer block from the valve. Air flows through the center of the valve and exits through an opening in the valve BETWEEN the 2 o-rings then goes up the transfer block port. That is how the transfer block is sealed to the valve.
I followed Bob's suggestions and removed the grip. Then it is fairly easy to replace the breech O-ring. So I am all set for this initial mods.Other mods would require opening up the barrel and air cylinder. I will probably do that later , to at least change all seals.
Greg I've got mine set so it drops off the reg at about 100bar, I suppose I could eke out a tad bit more power from it but for my purposes this is good enough.
Greg I turned the adjustment clockwise 1/8th turn from the out of the box settings, it's really impossible to accurately adjust a pcp without a chronograph. I also had to back off on the hammer spring tension because the way that it came from the factory it was set at coil bind.
Greg, turning the regulator clockwise will increase the power and the set point on the PP700.
That is the reason a lot of us put set screws at the breech end to hold that collar there that the barrel screws into. That way, you can unscrew the piece on the end and remove the shroud with no problems. Right now, the collar on the other end of the barrel at the breech is turning when you turn the piece on the end of the shroud. You need to figure out a way to keep the breech end from turning, and then the end piece and shroud will come right off
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