A1 platform needs low pressure of around 500psi, you can get away with high pressure if you do the spring mod on the front reg but its not ideal as the gun will run inconsistant FPS.
Most air systems do a low pressure kit for around 10 to 15 quid or just get a ninja reg which can be set very easily to low ,mid and high pressure.
Most air systems do a low pressure kit for around 10 to 15 quid or just get a ninja reg which can be set very easily to low ,mid and high pressure.