Your PCP Air Rifle and filling it
I must answer questions on filling options for PCP air rifles on a weekly basis other than when actually selling a PCP such as the Weihrauch HW100, Cometa Lynx or AirForce Condor. You have several options to choose from as I have listed here. I will give my opinion on each option though some may choose to disagree to a point, but that’s life and what I have found here works for me.
High Pressure Compressors.
A High Pressure Pump rated at 3,000 psi (200 Bar) is the MINIMUM requirement to fill a PCP from a compressor. A garage compressor is only rated to 220 psi (15 Bar) or thereabouts, depending on quality so forget about that. To get to 200 Bar you need a 3 stage or better still a 4 stage compressor with a high quality water trap as moisture is a key enemy in PCP cylinders.
Using a 4 stage compressor is an expensive way to go as they cost several thousand dollars for a quality unit though I am told there are some from China at around a grand. Think it through and look for reviews on anything that comes out of China as I have heard mixed opinions of their ‘shoe-box’ compressor and the like when used on a PCP.
I used to own a Dive Shop and I used the German Bauer Compressors and English Bristol 4 stage Compressors, both of which are high quality but expensive. If you go the way of a compressor, I would advise using a scuba bottle to decant the air into your PCP rather than direct filling. With direct filling you have short duty cycles in filling your PCP cylinder. I feel these short filling cycles are less preferable than longer filling cycles where you top up a Scuba bottle which in turn gives multiple fills for your PCP air rifle and does so with cool air. This way you save on wear and tear and decanting time into your PCP but you have the added cost of a scuba bottle and filling kit.
Scuba Bottle rated at 232 Bar.
One of the most popular Scuba bottles around is the 232 Bar as per image below. If you are thinking of going this route then I suggest buying a second hand Scuba bottle through Gumtree© or Ebay© as I have customers who have purchased bottle for as little as $50 each. Add $30 for testing and initial fill and you are ready to fill your PCP air rifle once you have got a filling kit.
I have the MDE Scuba Filling Kit (aka Charging Kit) for the 232 and similar necked scuba bottles (part#MT1483 – MDE Charger for PCP Air Rifles “A” Clamp Fitting) or the much cheaper Chinese Rhino version (part#AAN1425 Rhino PCP Valve for Scuba Charging. “A” Clamp Fitting). Both charging valves work well on PCPs. Prices can be found on my website in the PRODUCTS Drop Down Menu.
Scuba Bottle 300 Bar.
If you are an avid shooter and use your PCP(s) often then I seriously suggest that you look at the 300 Bar Scuba bottles, as the additional air pressure allows for many more fills before the bottle and the cylinder pressures level out at a barely efficient 2,500 psi or thereabouts. As you guys know, the 232 Bar doesn’t take many fills before the pressure drops below 150 Bar which is the barest minimum to fill most PCP air rifle cylinders.
As I shoot more than most guys, I have a 232 Bar Bottle that I use to fill empty PCPs up to around 1,500 psi (102 Bar) then I top up using my 300 Bar Bottle. This way it allows me to run the 232 Bar down to around a 100 Bar before I get it filled resulting in fewer trips to the Dive Shop and better time management.
NOTE: Care must be taken not to fill your PCP above 200 Bar when filling cylinders with a 300 Bar bottle as the higher pressures can cause serious damage to your air rifle and possibly you if you are in the way.
For AirForce PCP owners, I have found that most of them shoot the best at 2,700 psi and so there is NO benefit it racking up the pressure above that.
The DIN Scuba Bottles are recognisable by the charging port being a female screw in type as below. The DIN Charging Valve has a deep threaded screw in coupling that will fit both sizes of DIN bottles, that is the lower 200 Bar and the higher pressure 300 Bar.
At the end of the day guys, it’s my opinion based on years of shooting air rifle PCPs that a Scuba bottle is the way to go.
Excuse the Nitrox sticker on the side as I haven’t got around to taking it off……
Hill or similar PCP Hand Pump.
Lastly there is the 3 and 4 stage Hand Pump that requires you using your body weight rather than your arms to manually cycle the pump when filling your PCP air rifle.
Tip #1. Don’t rush guys, pump steadily and take a break every few minutes to allow the pump to cool.
Tip #2. Try several different body postures and weight transfers to find one movement cycle that is more comfortable as you may well have to pump up to 200 cycles on an empty cylinder. Tiring work…
The advantage of the Hill Hand Pump Mk4 (part# HP200) is that it requires no electricity, it is portable so you can take it into the field, it’s lightweight and easy to store.
On the negative side it costs around $440 AUD at the time of writing this. Furthermore, it is tiring work when you are filling a PCP air rifle in the field especially. Those of you slight of frame or overweight may find the pump strenuous to say the least as this method is not for anyone who lacks a basic level of fitness.
Before you jump on the phone and start asking me questions about this pump, click here and download the Owners Manual that will tell you all you need to know.
Summary on Filling PCPs.
PCPs do not like heat by way of hot air, as this leads to condensation and a drop in cylinder pressure as the air cools. Do not fill your PCP air rifle fast, always keep your hand near the neck of your PCP cylinder to monitor the heat. If it starts getting warm, then close off the air from the Scuba bottle or Compressor and slow the filling rate.
Tip 1. When filling a PCP try and stand on the “other” side of where the air probe or Foster connects in case a fitting or hose lets go. Trust me here guys, you wouldn’t want to be in the way….
Tip 2. Only fill your PCP with Compressed AIR and NOT Oxygen or any other gas. Stick to compressed air and the gun will do everything you need it to. Don’t try to reinvent the wheel by using some of these inert gases and mixtures. Nobody will thank you if it goes wrong.
The other thing that you PCP will not thank you for is moisture, so ensure that your compressor if you use one, has efficient water traps and dryer. If using a Scuba bottle them in all likelihood the air will be dry in your bottle as Dive Shops have stringent quality control of breathing air. When using a Hill hand pump, make sure you change the air-drying beads in the inlet manifold regularly – see manual.
Those of you new to PCP air rifle scene this may look like a lot of hard work and expensive outlay to fill your air rifle. However, I feel the Scuba method offers the cheapest and most effective way of filling your PCP air rifle, so if you are in the market for a quality PCP give me a call.