Cleaning and maintaining an air rifle or air pistol

• After every session, wipe the outside with a soft or lightly oiled cloth and dry off sweat and rain; that is the routine most manuals ask for.
• Clean the barrel from the breech towards the muzzle, with a pull-through or felt pellets, when groups open or on your maker’s interval; never with a wire brush or a steel rod, and never with a rod pushed in through a compensator.
• Oil almost nothing. A petroleum oil or WD-40 in a spring gun’s compression chamber causes dieseling; any oil in a PCP’s air system can detonate; the makers name silicone oil for seals, moly grease for a spring, and their own grease, thinly, for a cylinder thread, or none at all.
• Spring gun: never dry fire it, never store it cocked, oil the barrel hinge, and leave the piston seal and spring to a service.
• CO2: take the capsule out for storage; a drop of oil on its tip when you fit a new one, if your manual says so.
• PCP: fill with clean, dry air only; take the cylinder off after a session or after weeks, as your manual says, cap its thread, and never oil the valve.
• Store it unloaded, uncocked, dry and at room temperature, and let it warm up slowly when it comes in from the cold.

Less than you think, and the makers set the interval. Feinwerkbau’s care manual for its Model 900 series has the whole rifle wiped after each session, with a lightly oiled cloth to remove fingerprints and perspiration against corrosion, the barrel cleaned every 500 shots with dry cleaning wicks, and the seals inspected annually or when performance declines; its P8X pistol’s manual says the barrel inside should be cleaned if required. Air Arms writes that for target shooting many shooters clean only when groups open measurably, which may be every few thousand shots, not every few hundred, and that you should clean when there is visible degradation in performance, not on a rigid schedule; Tony Fouracres, writing for Air Arms, gives his barrel a light clean every 150 to 200 shots and before a competition. Anschütz, at the other end, has the barrel cleaned thoroughly after every use, and reaches for a bronze brush only at heavy fouling, 2 000 to 3 000 shots, or at the yearly inspection.

What tells you is the card. A group that has grown over weeks with the same pellets, the same hold and the same zero is the barrel’s or the pellet’s; Airgun pellets tells you how to test the pellet, and if it is the barrel, clean it and then expect, as Air Arms says, 20 to 50 shots before performance settles. Do not judge accuracy immediately after cleaning, and do not over-clean.

Every maker that gives a direction gives the same one: from the breech towards the muzzle, the way the pellet goes. Feinwerkbau inserts the cleaning wicks from the loading side and pulls them through in the direction of shooting, evenly and without jerking, so that contamination leaves by the muzzle; Walther cleans from the loading tray to the barrel and never inserts a rod through the compensator; Weihrauch pulls the cord only from the chamber to the muzzle; Diana inserts the rod from the breech end; Air Arms says cleaning should always move from breech to muzzle to protect the crown and, in its words, the accuracy.

The tools are a pull-through with a patch, or felt pellets. Walther names both for the LP500, commercial felt pellets to shoot through and cleaning patches on a line; Steyr says to shoot dry, not greased, felt pellets or cleaning strings through the evo 10; Weihrauch cleans the bore with felt cleaning pellets or a cord, only slightly oiled and fluff-free. VFG, which makes the felts, says the pressure of the shot expands the pellet so that it cleans the whole bore, and that two shot after a session leave the barrel clean, with oil-soaked ones followed by dry ones until they come out white. Anschütz is the exception: its 9015 manual allows no felt plugs or unapproved greases in its barrel at all. Follow your own manual.

Never a wire brush, never a steel-tipped rod: Weihrauch says they can seriously damage the rifling, Diana rules out wire brushes too, and Air Arms notes that rigid steel rods made for firearms can flex and scrape. Feinwerkbau cleans with no metal objects and no water. A barrel cleaned for storage is oiled lightly, and the oil is removed before the next shooting, Feinwerkbau says, with dry wicks until they show no oil; Anschütz has you fire about ten shots to restore consistent performance after de-oiling. Fouracres never sprays cleaning fluid directly into the barrel.

The first rule is what not to use. Petroleum-based oils, WD-40, 3-in-1 oil, aerosol lubricants and general-purpose products are not suitable for spring-powered air rifle actions, Air Arms says: applied to the piston chamber or compression tube they can cause dieseling, an uncontrolled ignition of oil vapour under compression, and excess lubricant in the compression chamber is the primary cause of it. Weihrauch puts the PCP rule in capitals: do not use oils or solvents intended for firearms in any PCP air gun, which can cause severe detonation; a separate warning says internal lubrication at those pressures can have an explosive effect; and never oil the connecting threads and valves of the air cylinder. Umarex says the same of its CO2 pistols: no petroleum-distillate oil or solvent, and no over-oiling.

What the makers do allow is specific. Air Arms: a silicone-based oil or grease for synthetic seals, including the piston seal and a very light film on the breech face; a moly-based grease for the main spring and its guide, applied sparingly at a full service and not in routine owner maintenance; a few drops at the barrel hinge. Weihrauch: resin- and acid-free oils, never too much, and a specialist gun oil on the metal parts after use and before storage. Diana: an occasionally oiled cloth on the blued outer parts. Walther: nothing on the LP500’s aluminium and carbon exterior, and the moving parts not serviced by the shooter at all. Feinwerkbau: no lubrication of the Model 900’s trigger unit, since excess impairs it.

The cylinder thread is where the makers part. Steyr greases the O-ring in the loading port and the O-ring at the cylinder socket of the evo 10 with acid-free silicone grease every 1 000 shots; Walther lightly lubricates the thread on the pressure reducer with acid-free silicone grease after about the tenth removal of the cylinder; Feinwerkbau applies a very thin film of its own grease to a dry thread and warns that lubricant in the valves can impair them or make them inoperable; Anschütz greases the valves and thread of the cartridge lightly with its own grease and warns of an explosion risk from oiled ones; Weihrauch never oils the thread or valve at all. Your manual, and only its grease.

A spring gun’s working parts were lubricated at the factory, and Weihrauch says the lubrication of the piston, piston seal and main spring is renewed only when the seal or the spring is exchanged; what the owner oils is the barrel hinge, slightly and at regular intervals. Air Arms lists piston-seal replacement or inspection as a professional job, and the moly on the spring as a service item. What you do watch for is the signs Air Arms gives that a service is due, a change in velocity or consistency, a rougher or heavier cocking stroke, a change in trigger feel, or any unusual noise in the firing cycle.

Two rules are absolute. Never dry fire a spring-piston gun, Weihrauch says, and avoid unnecessary dry firing of any airgun to prevent wear or breaking of parts; Diana calls firing without a pellet detrimental, because the free impact strains the mechanism. And never leave it cocked: Weihrauch says a main spring kept cocked for a longer period can lead to accidents and fatigues the spring, and never to put a gun away loaded or cocked; Diana says a rifle left cocked for long periods, loaded or not, weakens its mainspring. How a spring gun works, and what a gas ram changes, is in Types of air rifles and Types of air pistols.

Umarex’s rule for its CO2 pistols is the one that saves seals: do not store your air pistol with a CO2 cartridge in it, which it calls very important for the longevity of the seals, and remove the capsules before storage. The same maker has you put just a drop of oil directly on the tip of the cartridge before inserting it, never a petroleum-distillate oil, and its HPP, a 12 g capsule pistol, is cleaned every 250 shots with a maintenance capsule and its barrel with a little silicone oil on a cloth, never silicone dripped into the barrel. Keep a capsule out of heat: Umarex sets a maximum of 50 °C for storage or operation, which it says direct sunlight on a bright day reaches.

Fill with clean, dry air only: Steyr says only clean and dry compressed air; Weihrauch asks for air free of oil and water, divers’ quality to DIN EN 12021, and warns that a hand pump lets moisture into its cylinders; Anschütz fills to the same breathing-air standard and empties the cartridge slowly after about 20 fillings to let any condensation out. Feinwerkbau stores cylinders and refill bottles dust-free, and Weihrauch screws the dust cap onto the thread whenever the cylinder is off.

When to take the cylinder off is the makers’ second disagreement. Feinwerkbau says the Model 900 must not be stored under pressure, so the cylinder is disconnected after every training session, before any transport and in long-term storage, unscrewed at least until the air has escaped from the system; Anschütz recommends loosening the cartridge whenever the rifle is not in use, to spare the housing, valve, seals and springs; Weihrauch unscrews the cylinder, caps it and stores it after a session or for transport, which releases the pressure from housing, valves, springs and seals. Walther, on the other hand, finds disassembly unnecessary with regular use of the LP500 and has you unscrew the cylinder only when the pistol will not be used for several weeks, to preserve the seals; Steyr says the cylinder may be unscrewed at any time without being emptied. The cylinder itself has a ten-year life on every maker’s rules, Walther’s carbon cylinder retestable once, and the thread and valve take grease or nothing as the oil section says.

Store it unloaded and uncocked, with the capsule out of a CO2 gun and the cylinder off or on as your manual says. Walther keeps the unloaded LP500 in its plastic case in a dry room at room temperature; Feinwerkbau stores the rifle dry, dust-free and at a stable 15 to 25 °C, away from sunlight, humidity, radiators and damp cellars, with the cylinder separate and without pressure; Anschütz leaves the case open when the rifle is not in use so that moisture can escape, and Weihrauch warns that the foam lining of a case may react with the metal. Before months of storage, Air Arms runs a lightly oiled patch through the barrel and a dry one before shooting again. The cabinet and its lock are the law where you live; the safe setup for shooting at home is in Training at home.

The cold is the other enemy. Bringing a gun from cold into warm rooms forms condensation on the metal and inside the barrel, Anschütz says, and if it is not dried quickly it can cause surface rust; its routine after shooting is to let the rifle warm to room temperature with the bolt open, wipe the condensation off the outside and rub the steel parts with gun oil. Air Arms allows a gradual temperature change before sealing a gun in a case and wipes the metal down after shooting in the wet; Weihrauch, in extreme cold, warms the gun to room temperature before using it.

The owner’s routine ends at the parts under tension or pressure. A spring gun’s piston seal and main spring are a service in Air Arms’s words, and the parts whose exchange Weihrauch ties a re-lubrication to; a PCP’s valves and regulator are never opened at home, and Feinwerkbau says never to attempt to open a compressed-air cylinder. Feinwerkbau recommends a yearly service at an authorised gunsmith or at the factory, has seal kits for its compressed-air guns with the caveat that fitting them takes specialist knowledge, and says its repairs generally go through specialist dealers. When the trigger changes, the cocking stroke roughens, the gun loses pressure overnight or the groups will not come back after a clean, that is the moment.

Can I use WD-40 on an air rifle or air pistol?

No. Air Arms lists WD-40 with petroleum oils and aerosol lubricants as unsuitable for a spring gun’s action, where oil vapour under compression diesels, and Weihrauch forbids firearm oils and solvents in any PCP, where internal lubrication can detonate. Use silicone oil on seals and the maker’s own grease, thinly, where the manual says.

How often should I clean an airgun barrel?

When groups open, or on the maker’s interval: Feinwerkbau every 500 shots with dry wicks, Anschütz after every use with a brush only at 2 000 to 3 000 or yearly, Air Arms when performance visibly drops, which for target shooting may be every few thousand shots. Always from the breech towards the muzzle, and expect 20 to 50 shots before it settles.

Should I leave the CO2 capsule in?

No. Umarex says not to store an air pistol with a CO2 cartridge in it, to preserve the seals, and to keep capsules below 50 °C. Take it out at the end of the session, and put a drop of the maker’s oil on the tip of the next one if the manual asks for it.