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Airgun Technical Information



Most novice airgun owners are familiar with the Daisy BB gun. Some have access to a higher-powered pellet gun, a Sheridan or Benjamin pump airgun, or a CO2 gun from Crosman. There is a tremendous variety of air guns available. The great majority of modern airguns are powered by springs and fire a .177 or .22 caliber pellet between 500 and 1000 feet per second, developing energies in the range of 5 to 20 foot pounds. That’s not much, considering that even the lowly .22 short develops around 80 foot pounds of energy, but it’s more than enough for a variety of target sports and even hunting small game. If you have a specific question regarding airguns, please contact us with the model and issue and we will gladly try to address your concern.



Airgun Parts Diagram and Owner Manuals
    Many of our customers request “schematics” or “exploded parts diagrams” of various airguns. They mean a three dimensional drawing, technically named an isometric drawing, that shows the relationship of parts. That type drawing is extremely rare for anything manufactured before World War II (circa 1945). Prior to WWII parts diagrams were a plan view of all the parts spread out, sometimes organized by the type part, sometimes not organized at all, and never showing their relationship to each other. Isometric drawings were developed during WWII for the military. After the war, they began appearing for other mechanical devices like firearms and airguns. Many airgun company's did not produce isometric drawings of their airguns till the 1960s. Many of the drawings of airguns between 1945 and 1960 were made many years after wards by collectors, airgun companies, or others. We are happy to supply printed copies of the ones we have if you request one with your parts order. If you want it first, please look at the links below or send a self addressed stamped envelope, with your request, to the address on our “Contact Us” webpage.



    Airgun Seal Kits

    For Benjamin and Sheridan guns made from World War II to 1993 require a special tool, part number SHET4. Some Crosman guns made from 1924 to about 1970 require special tools. It is difficult to change the seals on Daisy spring action bb guns without a special tool to compress the spring. Click here for Seal Kit Listing.



    Airgun Powerplants

    The earliest airguns date back to the 17th century. The earliest airguns used two basic systems which today we’d call ‘precharged pneumatics’ and ‘spring air’ guns. Today there’s a much wider variety, but most if not all bear a strong resemblance to those original types.



    Airgun Spring Airguns

    Spring-air guns develop power via a piston propelled by a spring under compression. Cocking the weapon causes a piston to be drawn back in a cylinder, drawing air into the cylinder and compressing a coil spring. Pulling the trigger releases the piston, allowing the spring to propel it forward and force a large volume of air through a hole into the barrel, propelling the pellet down the barrel. Spring air guns can be as simple as a BB gun or as complex as a recoilless match air rifle. They can be simple, low powered guns or high-power rifles developing 30+ ft/lb of energy. In one modern design the coil spring is replaced by a gas strut containing air or nitrogen under pressure. Spring air guns generally develop a significant of recoil from the action of the movement of the piston, but it is possible to produce a recoilless spring air gun. One system, pioneered by Feinwerkbau in their 300B series of match rifles allows the entire action to slide on a set of rails. When the gun is fired, the barrel and action are allowed to slide rearward under recoil, while the stock remains motionless. This system is also used to RWS and Air Arms in some of their rifles. The other system, pioneered by RWS/Diana, uses two pistons moving in opposite directions to cancel out recoil. However, careful balancing and tuning of spring size and transfer port size and shape, combined with spring dampening compounds and devices, can drastically reduce recoil in a standard spring gun.



    Airgun Pneumatic

    The Pneumatic Airgun works a lever or piston to compress air into a reservoir. On firing, a hammer kicks a valve open and releases some or all of the air from the reservoir into the barrel. Pump pneumatics come in two basic varieties- single stroke, which require only one stroke of a lever to fill the reservoir, and multi-stroke models, which require multiple strokes to fill the reservoir. Single stroke pneumatics range from a few inexpensive Daisy and Crosman guns up through expensive field guns like the Dragon and match guns like the RWS 100. Single stroke guns have the advantage of being quick to cock, efficient is their use of muscle energy, and having a high degree of consistency from shot to shot. Multi-stroke pneumatics are generally found more at the lower end of the scale, ranging from around $30-$100 in price, though there are exceptions. Most are inexpensive guns from Daisy and Crosman, though there are the mid-priced guns from Sheriden and Beeman, slightly higher priced guns like the Sharp models from Japan, and unusual guns like the Korean Yeehwha shotgun. Multi stroke pneumatics offer higher power than single stroke guns, and the option of variable power as a varying number of strokes can be used to charge the gun. This is not necessarily an advantage, as trajectory changes radically with power level.



    Airgun Gas

    The Gas Airguns come in two varieties- those that use the small disposable CO2 cartridges, and those that are bulk-filled from a large tank. The guns using the disposable cartridges are again to be found mainly at the low of the price range, and include a number of inexpensive models from Daisy, Crosman and Marksman in the US, and a few other makers elsewhere in the world. The disposable cartridge gun is basically a US type, for the most part. Disposable cartridge guns today are found mostly at the low end, though there are some interesting guns to be had in the middle price range, most notable the new Crosman 10/77, a CO2 clone of the popular Ruger 10/22 rifle. In past years there was a wider variety of higher-power guns using disposable cartridges, including such oddities as the Crosman CO2 shotgun. One nice feature of CO2 is that it will maintain a constant gas pressure (about 900psi at room temperature) as it transitions from a liquid to a gas. This makes complex pressure regulation unnecessary. The downside is that CO2 has a near-zero vapor pressure at cold temperatures, making guns that use CO2 suitable for indoor use only in colder weather.



    Airgun Bulk Filled CO2

    The Bulk filled airguns are filled from an external reservoir of CO2. Most bulk filled guns are match pistols and rifles, though there are also some very unusual guns designed for hunting using CO2, mainly from countries with laws that make it difficult to own firearms. One of the best known is the Farco shotgun from the Philippines, a 28 gauge CO2 shotgun that can also fire saboted lead bullets or be fitted with a smaller caliber rifled barrel.



    Airgun Precharged Pneumatics

    While the term ‘precharged pneumatic’ could, technically speaking, refer to a wide variety of gun types, the term generally refers to a gun which is filled from an external tank of compressed air- usually a SCUBA tank. Precharged guns are basically a British invention, and while guns using a reservoir of compressed air have been around for a couple of centuries, most modern precharged pneumatics seem to derive from a modified gun that was designed for shooting tranquilizer darts through a large smooth bore. The top levels of field target shooting today are dominated by precharged pneumatics, though classes exist for other types of guns as well. In 1996 a small Swedish company started producing a three stage hand pump capable of charging pneumatic guns to 3000psi and beyond; this pump, distributed by RWS and others, has made owning a precharged pneumatic easier to manufacture.



    Airgun Airsoft

    Airsoft guns use compressed gas or springs to fire a soft plastic ball specifially designed to be relatively harmless if it strikes a person or object. They were originally conceived as realist looking toys for countries such as Japan where there is strong interest in firearms, but any and all firearms ownership by ordinary citizens is strictly prohibited. Modern Air Soft guns come in a dizzying variety of styles, and many are indistiguishable from the real firearms they seek to imitate. Such guns have found a place in realistic training, and in paintball-type competition. However, because of their low energies and limited accuracy they have no use in hunting or serious target shooting. Many people collect Airsoft guns as an alternative to collecting actual arms that are unavailable owing to cost or legal restrictions; airsoft guns are available that are almost indistinguishable from a wide variety of common military and fully automatic weapons.