Short answer: you fill a PCP from a high-pressure air source: a hand pump, a carbon fiber tank or a PCP compressor. Connect it to the rifle's fill port (usually a Foster quick-disconnect or a fill probe), fill slowly to the pressure the manufacturer specifies, bleed the line, and disconnect. Never exceed the rated pressure, and only use clean, dry air.
Your Three Air Source Options
| Source | Pros | Cons | Examples we carry |
|---|---|---|---|
| Hand pump | No power needed, low cost | Physical effort, slow at high pressure | Ask us about current options |
| Carbon fiber tank | Fast top-offs, many fills per tank, portable | Needs refilling at a compressor or dive shop | AirMarksman 9.0L 4500 psi, 6.8L |
| Portable compressor | Fill at home or in the field | Upfront cost, needs power and care | Nomad Nano, PCP Kong Lil Foot 2.0 |
See all compressors and air tanks. If you buy an AirMarksman 6.8L or 9L tank, we offer a tank air fill add-on.
How to Fill a PCP Step by Step
- Check the rated pressure. Find it in the manual or on the cylinder. For example, FX's manual lists 250 bar for the Impact M4 single-regulator setup, and the Karma EQ lists 310 bar.
- Inspect the fittings. Make sure the fill port and connector are clean and the O-rings are in good shape. FX supplies a 1/8-inch threaded quick connector with the Impact M4.
- Close the bleed valve on your tank or compressor.
- Connect the quick-disconnect to the rifle's male fitting, or insert the fill probe.
- Fill slowly. Open the tank valve gradually or start the compressor. Slow fills reduce heat and give more accurate readings.
- Stop at the rated pressure. FX notes that the rifle's gauges are indicators and not 100% accurate, so cross-check with the source gauge.
- Bleed the line before disconnecting, then refit the dust cap.
When to Refill
On a regulated rifle, refill before tank pressure drops to the regulator setting. FX's manual says to recharge when tank pressure is just above the regulator output pressure and not to use the gun below the set regulator pressure.
Compressor Tips
- Watch it. AEA's compressor listing says not to leave the compressor unattended.
- Use auto shutoff. The Nomad Nano, RovAir 4500 and Lil Foot 2.0 all list adjustable or automatic shutoff.
- Follow the oil and cooling rules. PCP Kong specifies 100% silicone oil only for the Lil Foot 2.0. The Western Road Runner has an oil sight glass.
- Check the limits. Air Venturi states the Nomad Nano and RovAir will not fill large SCBA tanks.
Comparing compressors? Read our compressor buying guide.
Air Quality and Safety
- Only use clean, dry air. FX warns never to use oxygen or any other gas.
- Moisture damages valves and regulators, so keep filters and separators serviced.
- Inspect carbon fiber tanks according to their markings and instructions.
- To degas a bottle for service or travel, use the right tool, such as the Saber Tactical bottle degasser and valve tool kit, and check compatibility first.
Frequently Asked Questions
What pressure should I fill my PCP to?
Fill to the pressure in your rifle's manual or on its cylinder, and never higher. It varies by model.
Can I use a scuba tank?
Some shooters use scuba tanks, but they typically hold lower pressure than carbon fiber PCP tanks. Check the tank's rating and your rifle's requirements. Carbon fiber tanks built for PCPs are more common.
How long does a portable compressor take?
Air Venturi lists approximately 14:30 minutes for the Nomad Nano to fill an FX Impact M4 (480cc) from 0 to 3625 psi. Topping off from partial pressure is faster.
What fitting do PCPs use?
Many use a Foster-style quick-disconnect. Others use a fill probe. Check what comes with your rifle and match your tank or compressor hose.
Why does pressure drop after filling?
Air heats up when compressed and cools afterward, so the gauge reading drops slightly. Slower fills reduce this.
Always follow the manufacturer manual, wear eye protection, and know your local laws before buying, carrying or shooting an airgun.
Talk to The Pellet Shop
Have a question about a specific rifle, caliber or setup? Visit our showroom in Westbury, NY, call or text (718) 450-4146, or email info@ThePelletShop.com. You can also browse every airgun we carry online. Specs in this article come from our product pages and manufacturer documentation and can change, so check the current product page before you buy.