AIR GUNS: CO2 CARBINES AND PISTOLS
Compressed air guns have become a bestseller in gunsmiths’ thanks mainly to their precision and ease of handling. They are mainly used in Spain for recreational shooting, however, in some other countries it it also permitted to use them for hunting. There is a wide variety of rifles and pistols on the market. Their classification can vary depending on how powerful the weapon is and its manufacturer, for example BSA, Gamo, Cometa, Crosman, Walther.... However, the most common classification is related to the loading system of the rifle or pistol. These are: spring rifle, CO2 rifle or PCP (or pre-compressed air) rifle. In this case, we are going to take a quick tour of CO2 compressed air rifles.
Co2 air rifle or carbine available in two caliber: 4.5 ó 5.5 mm.
The origins of pistols and rifles of this type date back to the mid-19th century. In 1959, a French scientist called Paul Giffard created one of his new inventions. It consisted of a rifle or carbine whose source of energy came from a gas, more specifically carbon dioxide or carbonic anhydride. This weapon was capable of taking 300 shots with a single load and its calibres were 6 and 8 mm. This weapon was so innovative that those who began to use it were unable to easily source CO2 refills for their rifles. Throughout the 20th century, various manufacturers such as Crosman applied Giffard's design to new weapons, thereby extending the CO2 rifle category. During the seventies, carbon dioxide rifles fell into decline as a result of the unstoppable progress of spring rifles. However, around the middle of the following decade, CO2 rifles made a comeback, achieving a privileged position in weaponry. Nowadays, it is a widespread type of technology used for both rifles and pistols, and an endless variety of models can be found on the market.
Giffard Design of a compressed air rifle with CO2
CO2 rifles use the gas as a propulsion system. These weapons have a reservoir to store the compressed gas which is passed to a valve by means of a loading mechanism. This valve is activated by a trigger which releases the CO2 to drive the pellet, which is shot out through the barrel. CO2 weapons require refills which must be changed when they run out and can be bought from specialised shops.
Charges for Co2 air rifle Co2 by Gamo´s factory
One characteristic of CO2 compressed air guns is that they are very easy to cock (a process which involves preparing the weapon for being shot). They also have a much lower recoil than a spring rifle would have for example, as the latter has a very significant recoil (the movement that the weapon makes on the shoulder of the shooter when the pellet is shot). There are marksmen who consider this to be a disadvantage of the CO2 weapon, as its recoil is quite far removed from that experienced with a firearm and this results in a loss of realism; whilst others consider it to be an advantage over other types of guns; it's a question of taste
Crosman 576 model air gun. Power is supplied via Co2 bottles of 12 grams.
Undoubtedly, the fact that the recoil of CO2 rifles is lower compared to spring rifles contributes to giving the weapon more precision. If the rifle has less vibration at the moment of release, the precision of the weapon will be greater. CO2 rifles are therefore weapons of great precision especially for shots from a short distance (10 metres).
Walther Co2 gun Nighthawk model. Caliber: 4.5 mm. With capacity for 8 units of Co2
The properties of the gas (CO2) determine the behaviour of the pistol or rifle. The most important factor to take into account in relation to carbon dioxide is the temperature, as depending on the external temperature the weapon will adopt changes in its behaviour. Hence, if the external temperature is low (below 10 ºC) the evaporation of CO2 that the weapon requires to be shot will be slower, thereby lowering the pressure. If, on the contrary, the external temperature is high (above 25 ºC) the evaporation of CO2 occurs more quickly. Basically, the pressure or speed of the shot from the weapon will be faster in warm environments; whilst at lower temperatures the speed will slow down.
In this respect, it must be taken into account that when CO2 is activated within the valve and it passes quickly from liquid to gaseous state by expanding, it cools quickly, whilst also cooling the weapon. Therefore, the pressure of the gas reduces, taking speed away from the weapon. Some studies have confirmed that in long series of shots from CO2 weapons the speed of the shot reduces by up to 30 m/s. To avoid this, it is recommended to leave a brief interval in time between shots so that the arm regains a normal temperature, with the recommended time being 15 seconds.
Co2 carbine Gamo Extreme model available in 4,5 y 5,5 mm. caliber
When using weapons of this type we must take into account a series of recommendations which will make CO2 rifles easier to handle. CO2 capsules or refills must be handled with care, especially during transport. This must be done in such a way that they are not hit or dropped on the ground. It is also important to never leave them out in the sun as the heat could make them explode. It is recommended to store them in places at normal temperatures (over 10 ºC and under 25 ºC) and it is also a good idea to check the valves of CO2 shotguns and pistols to guarantee that the weapon operates at its maximum efficiency. It is also advised not to store the weapon with CO2 refills inside it, to prevent the valve from becoming damaged. In the event of any CO2 leak when the capsule is loosened or due to any fault in the valve, it is recommended not to touch the affected area as the capsule will become frozen due to the gas leak and could cause serious cold contact burns to the marksman's hands. Finally, it is recommended to shoot CO2 weapons in areas which have good ventilation to avoid intoxication. Following this easy advice, you can make good use of your CO2 weapon, one of the compressed air guns offering greatest precision on the market.
CO2 pistol Beretta model M92 FS 4,5 mm. caliber capable of reaching a speed of 120 meters per second