Air pistols and revolvers are like any other firearm, they have to be regularly maintained and correctly operated. Cleaning and oiling them is a given and should be done as per the manufacturer's instructions. Always use the correct oils for metal, plastic, composite materials and silicone seals as per the manufacturer's instructions and failing any instruction, contact the dealer who supplied the weapon for advice.
Please read my articles on my air weapons which should provide you with a better understanding of my cleaning and oiling routines.
This article is relative to my own findings of common faults with CO2 gas air weapons BUT may not pertain to faults with your own weapons.
Air Pistols & Revolvers - Pellets Jamming the Firing Mechanism
A pellet jam in a revolver is a very rare event but it can happen. The most common causes of a jam of a pellet in a firing mechanism invariable applies to semi-automatic pistols, especially those with a blowback slide action during rapid fire.
Causes: Setting aside fair wear and tear in the magazine and the loading mechanics, the most common cause is that the user tends to attempt to glean as much gas out of the CO2 capsule whereby there is a sharp power and velocity loss and the pellet is jammed against the loading section of the barrel. If a Umarex CO2 capsule, especially when used with a Umarex blowback slide action pistol, can deliver an expected 60 shots with a certain weight of pellet, then seriously consider replacing the CO2 capsule with a new one at around 50 shots and try and avoid mixing non branded CO2 capsules. It may seem a waste but a pellet jam could mean the gun has to go back to the dealer or manufacturer to be disassembled or is too expensive to repair.
Pellet jams can also be caused by failing to maintain the gun properly by cleaning and oiling it. Revolvers are relatively easy to maintain as well as fixed slide pistols. Blowback slide pistols (some) can be field stripped to achieve cleaning and oiling of the slide and slide rail. The correct oils must be used as CO2 air weapons have silicone seals, metal to metal moving parts and in some cases, some plastic and composite bodies. If in doubt request assistance from a reputable dealer, who supplied the weapon.
Alloy pellets, especially 5.6gr pointed ones are prone to jamming in semi-automatic pistols, especially those with a blowback slide action. They never pose a problem in revolvers (Umarex Colts Tested) and are extremely accurate in Umarex Colts with tremendous velocity. I now only use RWS Match 10 Premium Line Kal 4.50mm 7.0gr .177 pellets in my blowback slide action pistols.
Oiled magazine mechanisms, especially oil on the rotation loading mechanism can jump or jam pellets, especially during rapid fire. Walther advise that if you are using a Walther OIL Maintenance CO2 Gas Capsule, you remove the magazine first. Once you have cleaned and oiled your air weapon and then when inserting a magazine, especially a plastic one, remove it again and make sure that any trace of oil from the internals of the gun are wiped down, especially the rotating section of the magazine where the pellets are housed. You may have to do this a few times to dispel any excess oil before firing the gun.
Air Weapon - Main CO2 Seal Failing
The most common fault is when this seal fails to seal 100% when the CO2 capsule is inserted and tightened up against it. It can cause the escape of CO2 gas at the seal and/or a lack of velocity when the weapon is fired. This pertains to pistols and revolvers.
Causes: Setting aside fair wear and tear, the most common cause is that CO2 capsules have been screwed up too tightly against the seal, whereby it has become weakened.
Another cause, is that the CO2 capsules used have repeatedly been fitted and screwed up into the seal without any lubrication on the CO2 capsule nozzle, which lubricates any friction and keeps the seal wet and preventing it from drying out. Ideally, you should pop a small drop of Crosman Pellgun Oil on the nozzle of the CO2 capsule before inserting it vertically in the butt of the gun and screwing it home until you hear the hiss stop (do not overtighten).
Another cause, is that the gun has been stored for a long period of time without any lubrication being applied to the gun's CO2 seal in the butt. Best to store with the magazine and CO2 capsule removed and Crosman Pellgun Oil is the ideal lubricant for oiling the seal when storing the weapon.
Air Weapons - Internal Seals in the Firing Mechanism Failing
The most common sign of a fault is when the weapon begins to lose its power and velocity; it is often first noticed when pellets show a marked sign in drop off pertaining to accuracy and target penetration.
Causes: Setting aside fair wear and tear, no lubrication has been fired through the firing mechanism. Crosman Pellgun Oil is ideal for preventing this problem by adding it to the nozzle of a CO2 gas capsule.
The air weapon manufacturer Umarex, takes lubrication of the internal seals a stage further by advising that a Walther OIL Maintenance CO2 Gas Capsule is regularly used to lubricate their air pistols and revolvers - usually after 10 x CO2 capsules are used to fire the gun. Walther advise that if you are using a Walther OIL Maintenance CO2 Gas Capsule, you remove the magazine first, which I do with my semi-automatic air pistols. In the case of my Umarex Colt Peacemaker Revolver, I leave my empty Umarex shell cases in the gun as each has a seal in its rear. I rotate my 30 x shells as I fire the Walther OIL CO2 Capsule.
When firing a Walther CO2 Maintenance OIL Capsule, turn the gun upside down to allow the oil in the CO2 capsule to fall towards the nozzle end and then fire the gun in that position with the barrel pointing at a slight angle downwards.