Regulator: "a valve for regulating the pressure of flowing gas or liquid to maintain a predetermined pressure". [dictionary.reference.com]
Originally Posted by CameronWilson
...power curve – well, what curve? All 40-plus were usable, with a 'sweet spot' lasting from start to finish, as on a regged rifle. As an added bonus, there was no gradual slow-down of power at the end of the cycle, either – once it had had enough, the rifle's velocity dropped like a stone within a few shots.[/B]
So the rifle has an arrangement of piston, o-rings and belleville washers which maintains a constant pressure in the air space between the firing valve and the main air cylinder. This has the effect of removing the power curve typical of unregulated rifles and makes the rifle behave exactly
like... a regulated rifle!
If it looks like a duck, and quacks like a duck...!