It should be a pretty interesting upgrade.
The cylinder in question is here:
http://www.redwolfairsoft.com/redwol...l?prodID=21830
Which is most likely used in here:
http://www.redwolfairsoft.com/redwol...l?prodID=22979
Which in turn was mentioned here:
http://www.airsoftcanada.com/showthread.php?t=41189
Redwolf rates the velocity at 450fps (I assume with .2's and
propane? duster?) which is what I get with my PDI 200 spring but it does it without the heavy cocking action... My question in addition to yours is how many shots do you get out of a full charge? 10? 20? Since you're using a sniper rifle you are probably using heavier ammo than most (.28's or .3's) so I think you'd be using more propellant per shot. PLUS you have to carry a propane canister around with you... Like I say.. an interesting upgrade. I'd love to try one for a day...