Using CO2 versus Compressed Air

[EdinAthens]

I scuba dive and have a tank so using compressed air is my first choice for pressure. However, a scuba tank is large, bulky and heavy and I see these small 20oz CO2 paintball canisters and I'm wondering if that is a worthy fuel source.

Since I am unfamiliar with CO2 and paintball equipment, can some of you "who know" - answer a few questions for me:
(everything on my gun is still at the factory settings)

1) What is the difference in shot power when using CO2?
2) I have been told that a CO2 tank is regulated to 800psi - is that true?
3) If 800psi is true, will the Marauder even fire a pellet with that low a pressure?
4) If the Marauder does work at 800psi CO2 - how many shots can be made before needing a refill?
5) If there is any other obvious CO2 advantage that I haven't asked about, please inform me.

I'm pretty certain that I am going to keep using air from my scuba tank...but my 80 cubic foot steel tank is really a pain in the rear to move around to fill the gun, especially with the short pressure hose that comes on the K-Valve adapter. That 20oz tank keeps smiling at me....

[EdinAthens]

I found an answer here: http://www.pyramydair.com/blog/2005/04/will-pcp-gun-function-same-if-i-fill.html

[sacshooter]

Just my .02 on using co2.

Co2 is great for plinking, and close range hunting, but it sucks for hunting at longer distances.

When I first got my .22 Talon SS rifle, I got it from Pyramid air with the Co2 adaptor instead of the high pressure tank.

The great part was that I could shoot forever on a 20oz paintball tank in the field. And when plinking I could burn through a tin of 250 pellets and still have air to spare.

If the game I was hunting could not be found. I would often take breaks and do some long range dirt clod and small rock sniping (still my favorate targets)

On the downside you will see a loopier trajectory and FPS swings.

When I would start hunting in the morning it would be shooting slower( because of the colder temp), and at high noon it would be shooting faster, then in late afternoon back to slower. This made it harder to take good headshots at longer ranges so it limited my effective hunting to range to 45-50 yards (with a steady rest and a good shooter).

The speed changes doesn’t affect the point of impact much at plinking ranges (for most people this is 30 yards or less)
and with co2 you will get a ton of shots per fill.

When I'm in the field shooting with HPA and my Talon or s410, I know I am limited to about 40 good fast shots. This means I can't take time out to hunt dirt clods and small rocks unless I am dragging one of my pony tanks along.

For hunting at ranges of 45 yards or more, for me it is HPA not co2.

Roger