AOA Blog

If you own a pre-charged pneumatic air rifle or air pistol, you’re going to need a way to fill the air reservoir, which generally means either a SCUBA tank or a high pressure pump.

Today we’ll be talking about FX’s three-stage high pressure hand pump, which is capable of achieving pressures as high as 250 bar (3600 psi).

When you open the box, you’ll see this:
           

If you remove the packing from the foot of the pump, and the manual from under the pump, this is what you’ll see: the main pump tube, the base plate under the handle grips, a zip-seal bag with some loose parts, and a 1/8-inch hose assembly.

Here’s how to get the FX pump ready for use.

1. Attach the “foot” to the pump. Grab the main pump tube and turn it upside down so the foot is facing you. Next, Position the base plate of the pump so that the two “wings” of the base plate are on the opposite side of the pump tube from the pressure gauge and so that the holes with the screw holes with the beveled edges are facing you. Position the holes in the base plate over the corresponding holes in the foot of the pump and attach the base plate using the two black allen screws and allen wrench from the plastic parts bag. Make sure the screws are snug.

2. Attach the external moisture trap to the foot of the pump. It screws in the hole just below the pressure gauge and should have a small silver seal on the screw fitting as seen in the picture below. Tighten it gently with a wrench to make sure the connection is snug.

             Here’s a picture of the external moisture trap in place:

3. Attach the filler hose to the external moisture trap just under the pressure gauge. Tighten it gently with a wrench.

             Here’s how the finished assembly should look:

4. Attach the fill adapter for your gun (at the other end of the filler hose) by gently tightening with a wrench. Here is where the fill adapter attaches: 

5. Close the knurled brass bleed screw (beneath to the filler hose) by turning it fully clockwise.

6. Connect your airgun to the filler hose.

Now you are ready to pump!

A Word or Two about Pumping Technique

Stand with at least one foot on one of the wings on either side of the pump’s foot.

Pull the pump handle up to the full length of its travel.

Push the pump handle back down. It will move fairly easily for about 2/3-3/4 of its stroke. When the pump reaches that portion of the stroke where the effort rises substantially, lock your elbows and flex your knees. Allow the weight of your body to drive the pump through the rest of the stroke. If you use this technique, you will find it much easier than if you try to drive the pump through its stroke with your arms alone.

Keep an eye on the gauge. It will rise a little bit with each pump. Know ahead of time what your target pressure is. The pump reads in BAR.

When you reach your target pressure, stop pumping, and open the knurled brass bleed screw quickly by turning it counter-clockwise to release the pressure and moisture in the filler hose before detaching your airgun.

According to the excellent manual that comes with the pump: Never operate the pump for over 5 minutes at a time, overheating may occur. Keep hands and other sensitive parts of the body away from the ventilation hole and make sure that other people are not in the way of the ventilation hole when bleeding the moisture trap.

Til next time, aim true and shoot straight.

–          Jock Elliott