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Multi-Pump

As a means of increasing the power, some airguns are designed so that several strokes of the pumping mechanism forces air into a chamber where it is held under high pressure. Each pump stroke forces more air into the chamber which increases the pressure which in turn increases the velocity of the projectile. The first Crosman airgun produced in 1923 was a multi-pump rifle in .22 caliber. Although some air rifles of the past were pumped up by pulling and pushing on a rod that was located below the barrel, the vast majority of multi-pump rifles are pumped up by swing the forearm downward and back up. The Crosman Models 760, 66, and 2100 are of this type as are the Benjamin and Sheridan models.

Because several pump strokes can produce a high pressure in the air reservoir, multi-pump rifles tend to be high powered models. The power achieved by a specific number of pump strokes depends on several factors, but the most important is the efficiency and capacity of the pump mechanism. Although the little Crosman 760 is an airgun of modest power that gives pellets a velocity of over 500 ft/sec, the Benjamin and Sheridan models are quite powerful. The .177 caliber Benjamin 397 can fire pellets at up to 800 ft/sec while the .22 caliber Model 392 drives pellets over 650 ft/sec as can the .20 caliber Sheridan rifles. Of intermediate power is the Crosman 2100 (which fires pellets at over 700 ft/sec), but it is a rifle that is capable of outstanding performance. Many of the classic Crosman rifles including the Model 140, 1400, and 2200 were so powerful that they were popular tools for hunting pests and small game. The modern multi-pump air rifle is capable of excellent accuracy as well as being a powerful airgun.

CO₂ Power

Although the use of CO₂ as a propellant gas began in France, Crosman pioneered its use in the U.S. almost 60 years ago. The advantage of using CO2 to drive projectiles lies in the fact that a small container of liquefied gas can be held within the gun and provide power for a large number of shots without any pumping. Crosman developed the Powerlet¨ which holds 12 grams of CO₂ which has become the standard of the industry.

Carbon dioxide is a convenient gas to use in airguns (although they strictly do not fire by air pressure, guns that are powered by CO₂ are still referred to as airguns). It is inexpensive, nontoxic, and noncorrosive. Another desirable feature of CO₂ is that the liquid exerts a vapor pressure that can be as much as 700-800 lb/in2 at temperatures of 70-75 oF. A pressure this high is sufficient to propel a .177 caliber pellet at velocities approaching 700 ft/sec or a .22 caliber pellet at almost 600 ft/sec. Therefore, it is possible to produce rifles powered by CO₂ that are versatile enough for most airgun uses. One outstanding Crosman CO₂ rifle is the .22 caliber Model 2260 which is a single shot bolt action rifle. A compact rifle known as the Model 2250 is also available, and the Model 1077 is a 12-shot repeater that is powered by CO₂.

The widest use of CO₂ is in pistols. A CO₂ Powerlet is compact enough to fit in the grip of the pistol which allows a magazine to hold several pellets and several shots to be fired without reloading or recharging a reservoir. The result is that the pistols can be made to resemble specific firearms very closely which provides an element of realism. A single shot pistol known as the Model 2240 holds the Powerlet in a tube below the barrel and operates as a bolt action. The new Crosman 2300 target pistol also functions in this way.

The major disadvantage of CO₂ as a power source is that the vapor pressure it generates is dependent on the temperature. On cold days, the pressure is lower which results in pellet velocity being lower. As a result, CO₂ guns are more practical in situations where the ambient temperature is above 60 oF.

AirSource®

Although the 12 gram Powerlet® cartridge is a convenient reservoir for CO₂, there are times when the number of shots provided may not be adequate for the sport. Crosman responded with the AirSource, a larger cylinder that holds 88 grams of CO₂. This much CO₂ provides enough propellant for as many as 300 shots. Crosman adapted the Model 2250 compact rifle and the Benjamin 392 to utilize the AirSource tanks. The Nightstalker utilizes the AirSource¨ tank as does a special version of the Model 1077.

Soft Air

Even though airguns are low in power when compared to firearms, there are times when even the power of an airgun is unnecessary. Soft air guns originated in Japan where the power level of anything that launches projectiles is severely limited. The term Òsoft airÓ refers to the fact that the guns fire by air pressure, but the pressure is much less than that produced in other types of airguns, especially multi-pumps and break action models.

Crosman produces an extensive range of soft air models. These include versions that resemble pistols, rifles, shotguns, and even submachine guns. The actual compression of air can be accomplished by manually cocking the gun for each shot, but it can also be accomplished by means of CO2 power or even electrical power supplied by a rechargeable battery. The result is soft air models that have many shapes and sizes.

Soft air guns fire plastic BBs that measure 6mm in diameter. Because the initial velocity is only about 250-480 ft/sec and the plastic bbs weigh very little, they lose velocity rapidly. Although soft air guns are not toys, they are suitable for use only at very short ranges. They are especially suitable for use indoors where low power is a must.