The regulator makes your marker more consistent. I am not familiar with the mongoose 2, so maybe you could email Diablo and ask if it would make much of a difference. I know it doesn't make much of a difference on Spyders.
sweet...i'm gettin a brand new mongoose 2 from my local pb store!!!(support ur pb store) .....i was just wondering if it would be good and if it was a ok gun!?!?!?!?!
Anywhere you can screw in a tank you can screw in a reg. All HPA tanks have built in regs that set the output to 850 or lower, or have adjustable output.
A reg with CO2 is a bit dumb.. Dave up for a compressed air tank isntead. You'll still be getting liquid CO2 with a reg. If you want, get an expansion chamber if your still shooting CO2.