By B.B. Pelletier
Filling a precharged pneumatic is easy when you use a scuba tank. What about using a hand pump? You’ll hear all sorts of conflicting reports about hand pumps, and it’s difficult to know what to believe, so I thought I’d take a stab at it.
Are hand pumps reliable? Yes, they are IF you don’t rush them! Their makers tell you to pump for a maximum of five minutes, then let the pump cool. I’ve found this to be good advice. If you just keep pumping, any hand pump available today will fail in a very short time. If you stick to five-minute sessions, it will last for many years.
How hard is it?
The higher you go, the harder it becomes. Any average adult should be able to pump up to 1,500 pounds per square inch (psi) with one hand! That’s anyone! From 1,500 psi to 2,000 psi, the pumping is easy, but it may take both hands. From 2,000 to 2,500, the effort starts to increase, but most adults should be able to do it with no trouble. However, from 2,500 psi to 3,000 psi, a hand pump is difficult to operate.
When the pumping effort becomes hard for you, you can stop pumping with your arms and let your entire body weight do the work by doing deep knee bends. That is a well-known pumping technique. But people weighing less than 150 pounds may find at some point that their entire body weight cannot make the pump handle go down all the way.
One more bit of advice; go all the way with the pump handle on both the upstroke and the downstroke. The pump does most of its work in the final inch of travel in both directions.
How many pumps?
How many pumps it takes to fill a gun will vary with the size of the gun’s air reservoir. A BSA Hornet has a tiny 75cc reservoir that fills very fast, while an AirForce Talon SS has a huge 490cc reservoir that fills slower. BUT, and this is an important point, you get more shots from a larger reservoir. In other words, the BSA may give you 20 shots at a certain power level while the Talon SS gives you 40 shots at a higher power level! So, consider what you get from each gun.
As it turns out, it takes pretty close to the same amount of air to deliver the same power from all precharged airguns of similar caliber. One gun may be a little more efficient than another if it has a longer barrel or perhaps a more efficient valve, but the rule of thumb with hand pumps is that they take one to three pump strokes per shot they deliver from any smallbore air rifle.
Pumping big bores is harder!
One BIG departure from everything I’ve said so far are the large bore precharged guns. That’s anything over .25 caliber. The big guns give from two to ten shots per fill, and they take just as many pumps to refill as the smallbores. Most shooters prefer to use a scuba tank to fill the big guys, but a hand pump allows you to go hunting without dragging that heavy tank along.
I’ll leave you with this: if you can follow the rules and let your pump cool between sessions, get a hand pump. If you are an impatient fellow, avoid hand pumps at all costs!