HPA pressure: how to hit your field's limit
How pressure sets the energy on HPA, why to step down in small amounts, and why figures outside 50–150 PSI are unreliable.
The regulator sets the power
On HPA the power comes from regulator pressure, not a spring. The regulator holds it steady, so temperature barely matters. Dwell, nozzle and barrel change the energy too, so chrono after every change.
Step down in small amounts
Energy does not follow pressure in proportion: 25% less pressure can take a replica from 2.2J to 1J. How much depends on the barrel, sealing, dwell and nozzle.
So step down in small amounts and chrono after each one. The same pressure gives different energy on different replicas.
Outside roughly 50–150 PSI the model stops being reliable: at low pressure the poppet does not open fully.
Air and shots
Only the air above the regulator setpoint does any work, so higher pressure means fewer shots per tank. Count the shots from a full tank once and the calculator derives the air used per shot.
HPA is among the most prone to joule creep and many fields chrono it with the BBs you play with, so calibrate with those.