Forget the scuba tank and get a hand pump. Five minutes of effort to pump up you cylinder and you never have to re cert a tank or run to the dive shop. You can get a good pump for the price of some of the tanks mentioned above. Below is a section of an article available at Pyramid Air.
You're about to take the plunge and buy your first precharged pneumatic (PCP) air rifle or pistol. Great! Now - how are you going to fill it? Scuba or hand pump? The choice is yours, but do you know everything you need to about the pump?
While I was the Technical Director at AirForce Airguns, I repaired all the hand pumps that came back, plus I worked on a small batch of returns from before I got there. There weren't many, so I probably fixed between a dozen and 20 hand pumps in three years. Doing it taught me some things about the hand pump that not too many people know. For example, I learned that the biggest cause for pump failure was not letting it cool down after a five-minute session. The only other cause of pump failure was owner disassembly. I never saw a pump fail for any other reason, nor did I ever see a bad pump that came that way from the factory.
We sold the what used to be FX pump from Sweden with a fill adapter for all AirForce airguns.
In this article, I would like to give you enough information to decide if a hand pump is for you. I'll do that by describing the operation in detail. Hand pumps that sell for more than $200 are almost as big a purchase as an air rifle, but you can't shoot one. It's more like a hot water heater. If it works, you don't think about it at all; but, when it breaks, everything in your life comes to a screeching halt. Homeowner or renter - it doesn't matter - we all need hot water. And, the owners of precharged airguns need high pressure air.
A scuba tank can take care of business very well, and a carbon fiber tank can do even better, but there will always come a day when you're down to 2,200 psi and the dive shop is closed. The hand pump never runs out of air. As long as you are breathing, your pump has what it needs to fill your airgun.
CAN you really pump to 3,000 psi?
Yes, you can. But it's not entirely easy; some effort is involved. If you generally avoid physical tasks, the hand pump may not be for you. But if you don't mind a workout for five minutes or less, the hand pump can be the best way to fill a PCP. You probably already know what it's like to pump a multi-pump pneumatic like a Sheridan Blue Streak. Well, they get up to around 1,000 psi, so pressurizing air is not foreign to you.
The hand pump is a more rugged version of what's built into the Blue Streak, and it goes up much higher - 3,000 psi. What makes it more difficult is that the guns you will fill often don't drop below about 2,000 psi, which is higher than the highest pressure the Blue Streak generates. You will pump up to around 3,000 psi for many PCPs, though not all of them go that high. So - you start pumping at the point where the air is already at a very high level, and you will take it up even higher. That's why the hand pump takes more effort than the pump that's built into a Blue Streak.
