Is CO2 right for you?
PUBLISHED: 16:22 28 October 2016
What are CO2 guns all about? The editor gives his view
A reader recently asked why we don’t feature more CO2-powered guns. Now I like CO2, and it makes perfect sense in certain applications, but it doesn’t work for everything. Let’s look at two of the most popular guns around to explain how they work, and when CO2 is just what you need.
The ubiquitous 12-gramme capsule sell by the millions, but not everybody knows how to use it. In essence, it’s a steel capsule filled with liquid carbon dioxide. At the top of the neck, the steel is quite thin and when you put the capsule into the gun a probe pierces this part. The liquid begins to turn into a gas and it’s this that releases its energy.
A small reservoir inside the gun holds a quantity of the gas ready to drive the pellet down the barrel. This is just the same as a pre-charged pneumatic airgun in most respects, and has many of the same benefits. When you cock the gun, a spring is compressed and when you pull the trigger, that drives a hammer that knocks open a valve in the reservoir for just a tiny fraction of a second.
During that time, some of the gas flows out and down the barrel to power the pellet to its destination. That’s a gross oversimplification, but near enough for jazz.
Crosman is one of the huge American manufacturers offering a huge number of CO2 guns. The classic 2240 is a bolt-action, single-shot pistol that’s been around forever and has formed the basis of a whole raft of models. I think ‘rugged and simple’ is the best description. There’s nothing fancy about them - they just work.
To power one up, you unscrew the large end plug from the chamber under the barrel, and drop in a 12-gramme capsule, narrow end first. Next, tighten the plug and face safely downrange. Cock the hammer fully and close it before disengaging the safety and pulling the trigger. You should get a satisfying crack and perhaps a little bit of gas from the muzzle. If not, tighten the plug and try again. The CO2 gas is now filling the chamber and all you need do is cock the bolt, drop in a pellet, close the bolt and fire.
The sights are the classic ‘post and notch’ set-up and although they’re quite basic, they work perfectly. My test gun was already on aim at 10 yards with my old favourite RWS Hobby pellet. Through the chronograph, it delivered an average velocity of 410 fps with the 11.9 grain .22 Hobby, which calculates out to around 4.5 ft.lbs. That’s a lot of power for a pistol!
This brings me on to a characteristic of CO2 that must be understood to get the best from it. The day I ran this test it was a pretty warm 25 degrees, but on a cold, frosty February day, it would have given a lower velocity.
Heat is a factor in converting the liquid CO2 to gas. If you shoot really quickly, the expansion has a cooling effect in the same way your fridge works. So, to get the best from your accuracy, you need to check your sights after the gun has had time to settle at the ambient temperature. Never take the gun straight from your nice warm house out into a chilly day and expect your zero to be spot on.
I mentioned this pistol is the basis for other guns in the range, and I felt the Model 6-2250XL was the ultimate example of that evolution. It’s grown a much longer barrel, a shoulder stock and an action that has scope rails. This configuration is well known as ‘the Ratter’ and for good reason.
You will always shoot more accurately with a rifle than any handgun and clean kills demand precision shooting. This handy little carbine is the ideal close-range ratting gun for use inside sheds and chicken coops. It makes 8 or 9 ft.lbs., which is easily enough to dispatch a rat cleanly, but not so much that you could damage the walls or roof of the building.
Having a scope fitted means you can see the kill zone of the rat or feral pigeon more clearly and lets you see better in low light, which is the norm on farmyard vermin duties.
Model 2240: £86.00
Model 6-2250XL: £199.00
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