NZGAC Hunter Education. Enabling better education and safer hunting practices.
NZ Hunter Education Course:
Module 4: AMMUNITION
Rifles and shotguns fire ammunition. A single piece of ammunition is called a cartridge or a ‘round’, although a shotgun cartridge can be called a shotshell or ‘shell’ for short.
While rifles fire a single bullet or projectile, shotguns fire shot, small pellets made of steel or lead. They can also fire a single projectile called a slug.
Cartridges are generally classified into two main types: rimfire and centrefire.
RIFLE AMMUNITION
> Rimfire
With a rimfire the priming compound is found in the rim of the shell. When the trigger is pulled the firing pin hits the rim and the impact detonates the priming compound.
This in turn ignites the powder creating the pressure that sends the projectile down the barrel.
Rimfire cartridges are only manufactured for rifles and pistols. They cannot be reloaded or used again. Bullets are generally made of lead or with a soft copper jacket and lead core. However you can obtain .22 shot shells for use on rats and such like at close range. Rimfire cartridges are generally used for target shooting and for small game such as rabbits, hares and opossums. They are not suitable for big game such as goats or deer and can cause unnessary suffering, as they lack sufficient power for a humane kill.
The most common rimfire calibres are .22 and .17.
There are several different varieties of each, for example:
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.22 short
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.22 long rifle
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.22 magnum
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.17 Hornady Magnum Rimfire (.17HMR)
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.17 Winchester Super Magnum
NB: It is illegal to possess or use a rimfire rifle in a National Park.
They can only be used on private property or a designated range.
CENTREFIRE RIFLES
> Centrefire
A centrefire cartridge such as a .308 Winchester or a .223 Remington has the primer compound in a small cup at the rear of the cartridge. When the trigger is pulled, the firing pin strikes the primer and ignites the compound which in turn ignites the powder, thus creating the pressure to send the projectile down the barrel. Most modern centrefire rifles operate around the 53,000 lb pressure mark.
Always make certain that you have the correct cartridge for the rifle you are using. Check by comparing the designation on the rear of the cartridge case with the markings on the barrel.
A cartridge for use in a centrefire rifle or a pistol consists of four distinct parts or components:
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Case – this contains the other three components and is generally made of brass, but can be made of aluminium. It is open at one end. (see image left)
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Primer – this contains the chemical compound that ignites when the firing pin strikes the primer and so ignites the powder.
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Powder – generally a smokeless powder, when ignited this fast burning chemical compound that generates the gases that propels the projectile or bullet down the barrel.
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Projectile or bullet – this is fired at game or a target. Bullets are generally made with a copper jacket with a lead alloy core or a solid copper alloy, although some shooters use cast bullets made from hard lead alloy such as linotype metal at lower velocities. Lead core bullets are now illegal in some countries.
A cartridge is a self contained unit, ready to be fired when loaded into a firearm.
> Cartridge uses and recommendations
Hunters have personal preferences when it comes to the rifles and cartridges they use. However hunters should use a cartridge appropriate to the game they are hunting to ensure a quick, clean and humane kill.
While deer and goats have been killed using .22 calibre rimfire rifles, these are not recommended for big game and are in fact illegal in areas controlled by the Department of Conservation.
Cartridges such as the .223 and 22/250 are used for deer stalking by experienced hunters, but for general hunting for medium sized game such as deer more powerful cartridges are generally recommended.
Cartridges such as the 7mm/08, .270 Winchester, .308 and 30/06 have stood the test of time and are a good first choice for deer, tahr and chamois. Be aware that more powerful cartridges used in modern lightweight rifles create greater recoil and can cause a shooter to flinch, making it more difficult to shoot accurately.
The ability to fire a rifle accurately with good shot placement and using good bullets is the key to having a successful outcome. More powerful cartridges do not make up for sloppy shooting!
