Firearm stunning for small 

plants

AMI Animal Care and Handling Conference

October 2013

Jennifer Woods, M.Sc. VPM - Animal Welfare
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Most Common Causes of Failed Stuns

Not the appropriate firearm for the species

Inaccurate placement of shot

Wet or damp ammunition

Failure to maintain gun
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Appropriate Training is Critical to Successful 

Firearm Stunning 
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Gunshot kills by mass destruction of the brain 

1st - shockwaves compress the tissues ahead of the bullet

2nd - laceration and crushing along the path or track of the bullet 

as it travels through the brain

3rd - formation of permanent and temporary cavities in the brain 

caused by the track of the bullet.
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The degree of brain damage inflicted by the bullet is 

dependent upon the firearm, nature of the 

ammunition and accuracy of the shot. 
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Firearm Basics

The basic ballistics of a bullet are: 

Weight or Mass - this is the weight of the grains in the bullet.

Muzzle velocity is the speed of the bullet the moment it leaves the 

muzzle. 

Muzzle energy is the kinetic energy of a bullet as it is expelled from 

the muzzle. The energy of the bullet is determined by the formula of 

half of the mass multiplied by the square of the velocity. KE=1⁄2mv2
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Firearm Basics

You want the bullet to maintain enough energy to effectively penetrate 

the skull of the animal, but not so much it passes right through. 

As the bullet passes through the air, it loses energy. The further it 

travels, the less energy it has as it hits the target. This why close range 

shots will not require the same amount of kinetic energy as a longer 

distanced shot. 

Shape of ammunition can also influence energy loss. Pointed bullets 

have less resistance then rounded bullets, losing less energy as they 

travel. 
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Firearm Basics

The calibre of the gun is based on the interior bore or diameter of the barrel. 

The larger the calibre (higher mass) = the more suitable it is for:

1. Larger animal

2. Animals with thick skulls or horn mass 

3. Longer distance shots 
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Firearm Basics

The barrel of a gun will be either:

Smooth 

Rifled (spiral grooves). 

When a barrel is rifled it causes the bullet to spin. The more spin a bullet gets 

from rifling, the more stable it is in flight making for a more accurate shot, 

especially at a distance.
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Selection of Firearm

The firearm needs to be powerful enough (kinetic energy) to 

produce irreversible insensibility, yet not so powerful that the 

bullet passes through the skull and into the neck of the animal. 
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Selection of Firearm

The three main considerations when choosing a firearm and 

ammunition are: 

The size of the animal

The thickness of the skull

The distance between the shooter and the animal
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When choosing between a shotgun and rifle 

considerations include:

Shotguns are best for close range shots (less than 20 feet)

Only slugs should be used in shotguns

Shotguns significantly reduce the chance of ricochet

Rifles are best for longer range shots (greater than 20 feet)

There is a greater chance of ricochet with a rifle

Ammunition from rifles have a greater chance of passing 

through the brain and into the neck of the animal. A shotgun 

slug with the equivalent energy will not. 
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Handling and restraint must be 

adequate to ensure the safety 

of the operator and 

the welfare of the animal. 
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Preparing to shoot:

Always be aware of your surroundings - location of 

people/other animals.

Always shoot with a clear background. 

Load your weapon

Wait for the animal to calm down/settle if necessary. Be Patient! Ideally, you will wait for the animal to be looking straight on at 

you.

Find the target on their head

Shoot
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LOCATION OF SHOT

The best place to penetrate the head is where the bullet/slug will 

meet minimal resistance with the most direct path to the desired 

areas of the brain, insuring maximum damage and destruction to 

the brain. 

Plan the trajectory so that the bolt or projectile travels

through the brain.
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Best Training Tool
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If an animal shows any signs of sensibility, you will need to 

immediately shoot the animal again.

If the first shot was not accurately placed, target to the correct 

spot. If the first shot was accurately placed, target 

approximately one inch above and slightly to the side of the first 

shot.
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Routine Maintenance & Storage

Only have enough ammunition out for the current shift (2 for 

each animal)

Always have a back up gun - rotate usage

Store ammunition in an airtight container

Regularly clean the gun
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