finding the optimal regulator and hammer spring setting for PCP
Assuming that there is no means to measure the regulator output pressure, is there a way to systematically determine the regulator setting and hammer spring tension given a wanted muzzle energy ? if anyone can point me to some online resources, it will be very much appreciated.
...is there a way to systemetically determine the regulator setting and hammer spring tension given a wanted muzzle energy ? if anyone can point me to some on-line resources, it will be very much appreciated.
Here's one approach, based on three simple (if approximate) facts:
1. For any combination of power plant flow factors, barrel length, etc., there's a minimum regulator setpoint pressure required to achieve a chosen muzzle energy (assuming the gun is capable of achieving that energy in the first place).
2. The lower the regulator setpoint pressure, the greater the fraction of reservoir initial charge that can be used before reservoir pressure drops below setpoint and the gun "comes off" regulation. All things equal, this setpoint, i.e., the minimum pressure defined by criterion #1, should correspond to the greatest number of usable shots per fill.
3. For any given regulator pressure, increasing hammerspring force will only increase muzzle energy up to a certain point. Beyond that point of diminishing returns, more force mostly only wastes air. Therefore this "certain point" should likewise correspond to the greatest number of usable shots.
These truisms suggest this sequence of adjustments.
1. Max out the hammer spring force adjustment (within reason!).
2. Adjust the regulator pressure setpoint to achieve the desired muzzle energy, plus a (small) margin.
3. Back off the hammer spring adjustment to lower muzzle energy to the target number.
At least this should get you close to the optimum settings with only a reasonable investment in time, air, pellets, and cut-and-try.