Air Gun Centre guide to Pumps and Bottles
A modern PCP needs to be charged with clean and dry compressed air and there are only two ways to do this; the pump and the diver’s cylinder (scuba tank)
The pump is very similar to the ones that you would use to inflate the tyres on a bicycle; but it is capable of supplying air at a much higher pressure. The biggest supplier of pumps in the UK is Hills. The Hills’ pump is a three stage, high volume pump and with a dry pack fitted, it will deliver an 80bar fill in about 90 strokes of the cylinder; this air will be 90% dry and this is more than acceptable for air rifles.
The main advantage of a pump over a cylinder is weight and longevity; you can attach a piece of para cord to a pump, sling it over your shoulder and head off into the wilderness and be totally self-sufficient for air; you will never need to travel to a dive shop or have a cylinder tested. A pump will keep you and your PCP shooting until the day you die.
There is however, a downside. A pump can be hard work As you start to fill your gun, it will be fairly easy, but as the pressure increases it will become harder and harder, the ability, however, to charge your gun with the power of your arms and legs with only a piece of toast for fuel can be a real advantage.
The diver’s tanks (also known as bottles and cylinders) are for me the most convenient way of filling up a PCP.
The first thing that you will see when purchasing a diver’s tank is the pressure rating, which will either be 232bar or 300bar. Now, this may not sound like a huge difference, but trust me, it is. A 232bar 12 litre tank will fill a S400 approximately 46 times before the tank needs to be refilled from a dive shop. A 12 litre 300bar tank will fill it approximately 106 times. (this figure is based on a S400 running at 11.5ftlbs and being filled when it gets to 100bar and is then filled back to 180bar). So, a 12 litre 300bar tank would enable you to fire over 5000 pellets between trips to the diver’s emporium, whereas a 232 bar would only let you fire 2300.
Most dive shops only sell 232bar, but here at the AirGun Center, we only stock 300bar cylinders as this is the best option for airgunners.
The final thing that you need to know about diver’s tanks is that they need to be tested every five years. This will cost about £40 and it will include a visual inspection of the inside of the cylinder and - if required -, a hydro test. (a hydro test is when they fill the cylinder with water under extreme pressure and make sure that the bottle does not bend or flex). After this, you will then get a sticker placed on the side of your diver’s bottle saying that it has been tested.
Without this sticker, no dive shop will fill your cylinder.
Below is a rough chart of the amount of fills you will get from a bottle.
S400 filling to 180 bar and refilling from 110bar
So what would I recommend? Well, if you are fit and strong, then a Hills pump is fine for your needs. If you live close to a dive shop or have a car, then a diver’s tank is a very easy way to fill your gun and a 7lttr 300bar fill will only cost about £7 at any diving shop and this will enable you to shoot 3000 pellets plus with any gun.
Come in and have a chat about your filling needs and we will be more than happy to advise you on what is best for you and your preferred rifle.
Bottle with hose and gauge: