How to Fill

The Marauder is a PCP air gun. PCP airguns are different than the multi pump air guns from the past. With a multi pump air gun you need to re pump up the air gun after each shot. With PCP air guns you generally fill (or charge ) a high pressure cylinder integrated in to the gun to pressures ranging from 2000 psi all the way up to 3,600 psi. Once the cylinder is charged you shoot away getting from 16 to 40 shots on average (Depending on the caliber and power settings) before you need to stop and recharge the gun.

So how do you recharge it?

There are basically three ways to charge PCP air guns:

Using a high-pressure hand pump.

Crosman sells a Benjamin PCP Pump.  The 3 stage high pressure air pump is specially designed to fill PCP airguns. The PCP Pump has a universal adapter and works with the Benjamin Marauder, Discovery and the Crosman PCP Challenger. Another hand pump option is the Hill Pump MK3. Hill MK3 hand pump 3-stage pump Up to 228 bar/3,300 psi Gen 3 pump requires less effort Field-stripped in 5 mins. Dry-Pac system removes 90% of harmful moisture Includes Dry-Pac & hose ending in 1/8 bspp female threads Made in England.  This pump is is nicer than the Benjamin hand pump, but little more expensive.  Please note if you go with the hill pump, you will also need the Air Venturi Foster Female Quick-Disconnect to 1/8 BSPP Male adaptor for it to mate up with the marauder male quick connect.

How hand pumps work

benjamin PCP hand pump

You connect the pump directly to a male foster fitting on the Marauder.  The foster air fitting on the gun has a one way check valve, meaning it will let air flow into the gun, but air will not flow back of the fitting.  Once the female fitting is attached to the gun, you close the bleed valve on the pump.  Then you start pumping.  As the air pressure rises in the pump, you will see the air gauge start to go up until the air pressure in the pump and hose equals or exceeds the pressure currently in the gun.  at that point you keep pumping until you reach the desired fill pressure which can very based on the caliber and how your gun is tuned.  Once the gun is filled to the desired pressure you turn the bleed valve on the pump.  this will release the pressure in the hose.  The check valve on the guns fill nipple keeps the pressure in the gun.


  • If you don’t shoot much and have the physical ability to pump the gun, live in a remote area where refilling high-pressure tanks, or a high pressure compressor is out of your price range, then this may be an option for you to consider.
  • The investment is relatively low cost.



  • It takes a lot of pumps to charge the gun.
  • It requires a lot of physical and downward pressure to fill a gun, especially when trying to fill to higher ftill pressures like 3000 PSI.  There is a workaround called air assist mod that some of our forum members are doing to speed up the process.  They modify the pump to allow them to hook in a small compressor to help assist the fill
  • If you weigh less than 140 you may find it difficult to effectively use your bodyweight to help pump the gun.


Using high pressure tanks.

small carbon fiber tanks

Scuba Tanks

SCBA Tanks used by fire and rescue personnel

Large nitrogen tanks leased from welding supply companies.


Using a high-pressure compressor.