Not all precharged pneumatic airguns have separate regulators, but most run what are known as ‘self- regulating valves’ that adjust to the changing pressure in the airgun’s air storage reservoir. A regulator is an additional device that dispenses a similar amount of air pressure for each shot, promoting shot- toshot consistency and therefore consistent accuracy downrange. Without a regulator, and despite the effect of the self- regulating valve, a PCP will produce what is known as a ‘power curve’, as the pressure in the air reservoir drops. Users of non- regulated precharged pneumatic airguns are advised to test their guns until they discover the ‘flattest’ part of the power curve, which is where the most consistent series of shots will be found. This can be most accurately acheived with a chrono’, but simply shooting at paper targets and noting pellet drop- off will work too.