© HSA 2016 Last updated 2014 

The Old School, Brewhouse Hill, Wheathampstead, Herts, AL4 8AN, UK 

t: +44(0)1582 831919 f: +44(0)1582 831414 e: info@hsa.org.uk w: www.hsa.org.uk 

Registered in England Charity No 1159690. Charitable Incorporated Organisation 

Humane Killing of Livestock Using 

Firearms 

This is the downloadable PDF version of the online guide. As such, some of the features are

missing, including video footage and web links. The online version may be accessed from

www.hsa.org.uk

Introduction

In all livestock production systems, no matter how well they are managed, there will be times when

animals have to be humanely destroyed in order to protect their welfare. In most cases, these

animals will be casualties which have not responded to treatment, or emergencies (animals with

serious physical injuries or in acute, unrelievable pain). The latter may occur: on‐farm; in transit; in

markets, lairages or collection centres; or as a result of accidents on the public highway, at

racecourses, shows or exhibitions.

Used properly, firearms provide one of the quickest and most effective methods of humane killing of

livestock. This publication has been written for all those, particularly veterinary surgeons,

knackermen, slaughtermen, farm staff and police firearms officers, who may be directly or indirectly

involved with the killing of large farm animals. It covers the humane destruction of cattle, sheep,

pigs, deer, goats and horses, using humane killers, handguns, rifles and shotguns, discharged at close

quarters, i.e. within 25 centimetres of the target – the animal’s head. All of these weapons fire free

projectiles (single bullets or shot‐charges) and their use is intended to kill the animals outright, with

no need for further action on the part of the operator. This has definite advantages in certain

situations where exsanguination or pithing would be undesirable or inappropriate.

These guidance notes explain how free projectiles kill animals, describe how the equipment should

be used and maintained, and highlight the associated animal welfare and operator safety

implications arising from the use and misuse of such equipment. It is strongly recommended that

instruction and training should be sought from a qualified and experienced operator before any

person attempts to kill an animal using any weapon which discharges free projectiles. It is also

recommended that, on the first few occasions at least, newly‐trained operators work under

experienced supervision, although it is recognised that this may not be possible in the case of

extreme emergencies.

As well as the moral and ethical responsibilities associated with the humane destruction of animals,

it is incumbent upon owners and operators of firearms to keep them properly maintained and

secured at all times in the interests of personal and public safety.

Please do not read further if you feel you may be negatively affected by the content.
© HSA 2016 Last updated 2014 

The Old School, Brewhouse Hill, Wheathampstead, Herts, AL4 8AN, UK 

t: +44(0)1582 831919 f: +44(0)1582 831414 e: info@hsa.org.uk w: www.hsa.org.uk 

Registered in England Charity No 1159690. Charitable Incorporated Organisation 

Important Points About This Website

This guide is intended to instruct operators in the proper and humane use of firearms for the

slaughter and killing of cattle, pigs, sheep, goats, deer and horses. In order to safeguard the welfare

of the animals to be killed, it is necessary for the guide to be both thorough and illustrated. As such,

some people may find some of the descriptions and graphics upsetting. Please do not read further if

you feel you may be negatively affected by the content.

All firearms are potentially lethal. You are advised to read the safety section of these notes with

particular care. If you are in any doubt as to any aspect of the operation of this type of equipment,

you should consult the manufacturer. In no circumstances can the Humane Slaughter Association

(HSA) accept any liability for the way in which firearms are used, or any loss, damage, injury or death

caused thereby, since this depends on circumstances wholly outside the HSA’s control.

The HSA aims to provide up‐to‐date and accurate information. If you have suggestions for improving

any of the material included in this guide please let us know at info@hsa.org.uk or using the contact

details provided at the HSA website.

A paperback version of this guide (published 2005) is also available to purchase at a cost of £5

(including postage). Contact the HSA for further details.

Killing with Free Projectiles

The purpose of discharging a firearm from close quarters at an animal’s head is to kill the animal

instantly. The free projectile, which may be a bullet or a charge of lead shot, achieves this by

destroying the part of the brain which controls breathing and other vital functions: the medulla

oblongata (the brain stem). In the split second prior to this, the projectile should also pass through

the cerebral cortex (upper brain) and the cerebrum (mid‐brain), causing extensive damage and

destruction (Figure 1). This damage, in addition to the concussive effect of the impact of the

projectile, will render the animal instantaneously insensible and the subsequent destruction of the

brain stem will prevent any possibility of recovery. 

 
© HSA 2016 Last updated 2014 

The Old School, Brewhouse Hill, Wheathampstead, Herts, AL4 8AN, UK 

t: +44(0)1582 831919 f: +44(0)1582 831414 e: info@hsa.org.uk w: www.hsa.org.uk 

Registered in England Charity No 1159690. Charitable Incorporated Organisation 

Figure 1: Lateral view of a mammalian brain 

Key: Upper brain/cerebral cortex (1), Midbrain/cerebrum (2), Brainstem/medulla oblongata 

(3), Spinal cord (4) 

 

Physiological Principles

The physical principle behind killing with free projectiles is the transfer of high levels of kinetic

energy (the energy of movement) in an extremely short time from the projectile to the animal’s

brain. If the correct type of projectile is used, the resulting damage should be sufficient to kill the

animal outright. Kinetic energy (KE) is a product of half the mass (m) of an object and the square of

its velocity (v). It is expressed by the following formula:

KE = 1⁄2mv2

The effect of the above relationship on the muzzle energy of a projectile is shown in Table 1. Muzzle

energy is expressed in joules (J), mass is expressed in kilograms (kg) and muzzle velocity in metres

per second (msˉ1). In these examples the mass of the projectile in both cases is 5.51g and the muzzle

energy required for an effective kill is 200 J.

Table 1 Relationship between mass, velocity and muzzle energy of a free projectile 

 Muzzle velocity of free projectile

275ms ̄1 200ms ̄1

Mass of projectile 5.51g (0.00551kg) 5.51g (0.00551kg) 

Muzzle energy (KE =

1⁄2mv2) 

208 J 110 J 
© HSA 2016 Last updated 2014 

The Old School, Brewhouse Hill, Wheathampstead, Herts, AL4 8AN, UK 

t: +44(0)1582 831919 f: +44(0)1582 831414 e: info@hsa.org.uk w: www.hsa.org.uk 

Registered in England Charity No 1159690. Charitable Incorporated Organisation 

It can be seen from Table 1 that a decrease of a little over 25 percent in muzzle velocity reduces the

muzzle energy by nearly 50 percent, leaving it well below the effective kill level. Therefore, it is

imperative to use a sufficiently powerful charge to propel the projectile at the optimum velocity. Any

factor which impairs the velocity of a projectile, such as an underpowered charge, will have the

effect of reducing its muzzle energy, with consequent implications for animal welfare.

Physiological Effects

When an animal is correctly killed with a shot to the head with a free projectile, be it a bullet or lead

shot, it will collapse immediately, stop breathing and may bleed profusely from the entry wound, the

mouth and/or the nose. There may or may not be immediate exaggerated tonic activity of the

muscles, or the carcase may appear completely relaxed. After a lapse of up to one minute, the

carcase may start to twitch and, in some cases, convulse quite violently (especially pigs). This is

normal in an animal which has been shot correctly. If in any doubt as to the effectiveness of the

shot, check the abdomen for absence of rhythmic breathing and the eye for absence of corneal

reflex, before deciding if it is necessary to shoot the animal again. The convulsions will start to

subside after a time (up to one minute) and eventually cease, leaving an initially limp carcase which

will then, in due course, go into rigor mortis.  

Indicators of an effective shot:

• Animal collapses immediately and stops breathing

• Carcase can be tonic or relaxed

• A fixed, glazed expression in the eye

• No corneal reflex

• Convulsions may occur after a lapse of up to one minute

Ballistics

The science of projectiles and firearms is defined as ‘ballistics’ and it can be divided into three

distinct categories: internal, external and terminal. Internal ballistics is concerned with what

happens within a time span of about two milliseconds, from the impact of the firing pin or striker, to

the exit of the bullet or shot‐charge from the muzzle end of the barrel. External ballistics is

concerned with the flight of the bullet or shot‐charge after leaving the barrel. Terminal ballistics

deals with that which takes place when the bullet or shot‐charge strikes the target.  

When using firearms to kill animals at close quarters, it is the terminal ballistics that are most

relevant. During the short period of interaction between a projectile and its target, the projectile will

undergo some degree of distortion or disintegration and the target will be pierced and subsequently

damaged. The amount of distortion and ensuing damage is dependent upon the mass of the

projectile, its design and construction, its striking velocity, the angle of incidence and the nature of

the target.

It is very important to appreciate that whatever weapon is chosen to carry out the killing of the

animal, that weapon is only the means of delivery. It is the projectile discharged from the firearm

which kills the animal, or not, as the case may be. Bullets or shot‐charges used for humane

destruction must have the properties which enable them to transfer sufficient energy to concuss the

animal instantaneously, penetrate the skull to a level beyond the brain stem, and distort sufficiently

to destroy much of the brain, brain stem and upper spinal cord.  
© HSA 2016 Last updated 2014 

The Old School, Brewhouse Hill, Wheathampstead, Herts, AL4 8AN, UK 

t: +44(0)1582 831919 f: +44(0)1582 831414 e: info@hsa.org.uk w: www.hsa.org.uk 

Registered in England Charity No 1159690. Charitable Incorporated Organisation 

For these reasons, the ideal ammunition is one which expands upon impact and dissipates its energy

within the brain cavity. The ideal performance of an expanding bullet is achieved when the nose

material peels back upon itself to form the classic ‘mushroom shape’ at the correct depth of

penetration in the animal’s head. This expansion must be achieved without the bullet breaking up or

suffering an unacceptable degree of weight loss. The expanded bullet should also utilise its potential

for tissue destruction at the optimum point of penetration, to cause maximum destruction in the

internal area containing the mid‐brain and brain stem. At the same time, however, the bullet should

not over‐penetrate and cause consequent danger to objects or persons beyond the intended target.

Ammunition must:  

• Concuss

• Penetrate

• Distort

• Destroy

Equipment

The use of free projectiles for the slaughter or killing of animals is not limited to the single shot, free‐

bullet humane killer, as widely used by veterinary surgeons and knackermen. Other types of

handguns (adapted or otherwise), rifles and shotguns can also be used with equal effect. Often, the

use of a shotgun may be preferable to other methods for both animal welfare and operator safety

reasons. Indeed, where emergencies arise on farms, shotguns are often more readily available than

any other weapon.

The most commonly used equipment includes:

• Humane killers (specifically manufactured/adapted, single‐shot weapons and ‘Bell Guns’ of

various calibres)

• Shotguns (12, 16, 20, 28 bore and .410)

• Rifles (.22, .243, .270, .308)

• Handguns (various calibres from .32 to .45)

Legislation

Legislation controlling firearms differs across the world. Operators must ensure that they operate

within the bounds of relevant national legislation. Contact your local authority for information

before obtaining or using any firearm.

Humane Killer

A purpose‐made, single‐shot weapon, which has a chamfered muzzle and vented barrel to facilitate

its use with the muzzle end of the barrel in full contact with the target.

There are two types of purpose‐made humane killers; the Greener ‘Bell Gun’ (no longer available

new, but still widely used; originally manufactured in .310 calibre, but many have now been

converted to .32); and the single‐shot pistol (usually .32 calibre).
© HSA 2016 Last updated 2014 

The Old School, Brewhouse Hill, Wheathampstead, Herts, AL4 8AN, UK 

t: +44(0)1582 831919 f: +44(0)1582 831414 e: info@hsa.org.uk w: www.hsa.org.uk 

Registered in England Charity No 1159690. Charitable Incorporated Organisation 

Both can be operated in full contact with the target and fire a single, round‐nose, lead bullet which

will kill outright conventional farmed animals of all sizes. Certain types of humane killer can only be

used in full contact with the animal’s head, because they feature a double safety action which

requires the muzzle to be pressed against the target in order to overcome an internal safety device

and put the breech block into contact with the firing pin. The most common of these is the Greener

‘Safti‐Killer’ (originally manufactured in .22 and .310 calibres, many have now been converted to

.32).

The single‐shot pistol resembles a traditional handgun, but differs in that it has no magazine and the

muzzle is chamfered and vented to facilitate shooting when in full contact with the target. It is held

and operated with one hand; this allows the operator to restrain the animal, if necessary, while

shooting. The Greener ‘Bell Gun’ requires two hands to operate, but it is favoured by some users,

especially when killing horses.

When using humane killers it is of utmost importance to use only the specially loaded ammunition

for killing animals at close range (round‐nose, lead bullets, available from the manufacturers and

specialist gunsmiths). Anything else may increase the chances of the projectile not penetrating

adequately; or passing through the animal without killing it, and posing a grave danger to the

operator and anyone nearby. It is very important to ensure that if the bullet should pass out of the

animal’s body it will not ricochet off concrete walls or floors. Hence, great care must be taken to get

the direction of the shot correct when inside buildings.

Purpose‐made humane killers are designed to be used in full contact with the animal’s head.

However, in practice some animals will move if contact is made. If this should happen, fire from as

close as possible, preferably within 5 centimetres.

It is possible to obtain multi‐shot humane killers which have been crudely adapted from standard

weapons, e.g. 9mm, .38 Special and .357 Magnum. The modifications have often proved to be

inadequate, therefore the HSA recommends that these types of weapon should not be used.  

Shotgun		

A long‐barrelled, smooth‐bore gun, normally used for discharging small shot at modest ranges.

Shotguns are the most common weapons found on farms. Often used for control of wild animals and

game shooting, they are a very effective means of killing all species of farm animals in an emergency

and, if used properly, are equally effective and much safer than rifles and handguns. They should be

used from a short distance (5‐25cm from the target).

For all conventionally farmed livestock species, a 12, 16 or 20 bore shotgun may be used with No. 4,

5 or 6 bird‐shot; (a 28 bore or .410 can be used if nothing larger is available, but should not be used

on mature bulls, or pigs weighing over 100kg). The muzzle should be held from 5‐25cm from the

animal’s forehead, aiming down the line of the neck into the main bulk of the body. On no account

must the muzzle of a shotgun be held directly against the animal’s head, as this could result in a

burst barrel and severe injury to the operator. Ordinary sized bird‐shot is capable of inflicting

massive injuries when it strikes as a compact mass. When used correctly the shot, in effect, strikes

the skull as a single, large‐calibre missile measuring approximately 2.0cm in diameter (when using a

12 bore). This has considerable initial penetrating power, due to its relatively high velocity and mass.

However, once inside the skull, the pellets within the shot‐charge will separate and disperse within

the brain cavity, killing the animal outright. Contrary to common belief, the use of a shotgun does
© HSA 2016 Last updated 2014 

The Old School, Brewhouse Hill, Wheathampstead, Herts, AL4 8AN, UK 

t: +44(0)1582 831919 f: +44(0)1582 831414 e: info@hsa.org.uk w: www.hsa.org.uk 

Registered in England Charity No 1159690. Charitable Incorporated Organisation 

not blow the animal’s head off; there is a relatively small entry wound, but the brain is completely

destroyed (see Figure 2). This is a much safer and usually much more readily available method than

using a free bullet.

Figure 2 Effect of 16 bore shotgun blast from a 

distance of two inches

In the hands of a competent operator, the shotgun is probably the best piece of equipment available

for the humane destruction of most large animals.

In exceptional circumstances (e.g. an agitated bovine in an open space which cannot be approached

safely), shotguns can be used to kill large animals from a distance. In such cases, shotguns with

open‐choke barrels are used in conjunction with special cartridges loaded with solid slugs (N.B. in

the UK such use is subject to additional certification and may only be carried out by specially trained

and licensed personnel, usually police officers).

Rifle		

A small bore, long‐barrelled gun, usually fired from the shoulder, the bore of which has been scored

with spiral grooves to impart spin on the bullet.

Rifles are capable of driving a bullet of a given mass at a greater velocity than would be the case for

a handgun. They are, therefore, extremely dangerous and should only be used as a last resort. The

most common rifles in use on farms are general purpose .22 inch rim‐fire, telescope sighted .22 inch

centre‐fire, .243 inch centre‐fire and larger bore centre‐fire weapons. The .22 inch rim‐fire are

usually used for vermin control (rats and rabbits) but can be used effectively, when loaded with the

correct ammunition, to kill young cattle, horses, sheep, deer*, goats, and pigs up to 100kg, when

shooting from a short distance (from 5‐25cm away). However, they do have limitations in that there

is no margin for error in respect of position and angle of incidence.
© HSA 2016 Last updated 2014 

The Old School, Brewhouse Hill, Wheathampstead, Herts, AL4 8AN, UK 

t: +44(0)1582 831919 f: +44(0)1582 831414 e: info@hsa.org.uk w: www.hsa.org.uk 

Registered in England Charity No 1159690. Charitable Incorporated Organisation 

If a .22 inch rim‐fire rifle is to be used for killing livestock, the muzzle should be held from 5‐25cm

away from the animal’s forehead and aimed down the length of the neck into the main bulk of the

body; on no account must the muzzle of a rifle be held directly against the animal’s head, as this will

result in severe injury to the operator. Always use a round‐nose, lead bullet; if there is any doubt

about the ammunition available, call in outside help, e.g. a knackerman. The same precautions for

operator safety apply as for the free‐bullet humane killer. These weapons fire a bullet with a muzzle

energy of approximately 145J only: therefore they should never be used in an attempt to kill aged

animals with very hard skulls, such as boars, bulls and rams.

The larger calibre, centre‐fire rifles are more specialised weapons, often used for shooting deer. They

offer greater projectile velocities and subsequent kinetic energies than the common .22 inch rim‐

fire, and as such they do not fall into the categories of weapon which can be used at close quarters.

These weapons can effectively kill all sizes of cattle, horses, sheep, goats, deer and pigs, but they

should only be used from a suitable distance, in an outdoor location with a safe backdrop, and by an

expert marksman. They come into their own where an injured animal cannot be approached, but is

in a suitable environment to be shot safely from a distance.  

*in England and Wales, under the Deer Act 1991, it is illegal under any circumstances to shoot deer

with a rifle of less than .240 calibre. Anyone doing so may be liable to prosecution.

Handgun		

A small, short‐barrelled, rifled firearm, which can be held and fired with one hand.

There are two important points to remember when using a general‐purpose handgun to humanely

kill animals. First, the muzzle must never be placed in direct contact with the target: shoot from a

distance of 5‐25cm and aim down the length of the neck into the main bulk of the body. Second,

make sure that the ammunition is suitable for the task: most commercially available handgun

ammunition is of the ‘wadcutter’ type and is loaded for target shooting. Although this type of

ammunition is used by some individuals for shooting animals, it is not suitable and it should be

replaced immediately with round‐nose, lead bullets (see Ammunition section). The same

precautions for operator safety apply as for the free‐bullet humane killer.

Note

In the UK, some handguns are exempt from the general ban on their ownership brought in under the

Firearms (Amendment) Act 1997. An exemption is granted provided the guns are used solely for the

humane destruction of animals and that this purpose is clearly stated on the individual’s Firearm

Certificate. In an effort to reduce the potential for criminal use, some licensing authorities may put

pressure on the operator to have the capacity of the magazine or cylinder reduced to one or two

shots. The HSA recommends that owners of such weapons hand them in to the local police authority

and equip themselves with a purpose‐built .32 humane killer. Such a weapon should come supplied

with the correct ammunition.

Silencer		

Silencers, also known as ‘sound moderators’, can be used in conjunction with some models of

humane killers and handguns. The attachment of a silencer significantly increases the length of the

barrel, and the weight and balance of the weapon. These physical changes can have practical

implications for the operator, making the use of the weapon more difficult in some circumstances.
© HSA 2016 Last updated 2014 

The Old School, Brewhouse Hill, Wheathampstead, Herts, AL4 8AN, UK 

t: +44(0)1582 831919 f: +44(0)1582 831414 e: info@hsa.org.uk w: www.hsa.org.uk 

Registered in England Charity No 1159690. Charitable Incorporated Organisation 

For example, increasing the length of the barrel makes it less easy to position the instrument at the

correct angle, especially when short people are trying to shoot larger horses.

Silencers are most effective on some older models of humane killers, and on semi‐automatic handguns.

However, they do not significantly reduce the report when used on revolvers or humane killers which

have been adapted from revolvers. This is because a sizeable proportion of the propulsive gas escapes

around the front end of the cylinder and is not contained within the barrel of the gun. There is also some

evidence to suggest that silencers can reduce the muzzle velocity (and subsequently the muzzle energy)

of the ammunition. It may be better not to use a silencer for very large and/or aged bulls, rams or boar.

Ammunition

The type of ammunition used for killing animals is critical. It must have sufficient energy to

immediately concuss the animal and penetrate far enough to destroy the vital areas of the brain

which control breathing and circulation.

Bulleted Ammunition

In most cases where animals have not been killed effectively by a free‐bullet weapon, the wrong

type of ammunition has been used. Commonly the problem is due to using underpowered

ammunition designed for use in target shooting, which therefore fails to penetrate; or to using

copper‐jacketed ammunition which over‐penetrates without distorting enough to cause sufficient

damage to the brain. The best way to avoid these problems is to use only a purpose‐made humane

killer in conjunction with the manufacturer’s recommended ammunition. Broadly speaking,

ammunition for humane killers should comply with the following criteria:

• Have a minimum calibre of .32 inches

• Generate a minimum muzzle energy of at least 200J

• Be round‐nose, lead bullets to facilitate penetration and distortion

Bulleted ammunition for all calibres of firearm is commercially available. Much of this ‘commercial’

ammunition is intended for target shooting at relatively short distances and is of the type known as

‘wadcutter’. Bullets in this category have a flat nose with a raised edge to facilitate cutting a neat

hole in a paper or cardboard target and, as such, they are not suitable for the humane killing of

livestock. Different types of commercially available ammunition are compared with the standard

Cash Humane Killer ammunition in Table 2. Those with a muzzle energy less than 200J are not

recommended for killing large or aged animals.

   
© HSA 2016 Last updated 2014 

The Old School, Brewhouse Hill, Wheathampstead, Herts, AL4 8AN, UK 

t: +44(0)1582 831919 f: +44(0)1582 831414 e: info@hsa.org.uk w: www.hsa.org.uk 

Registered in England Charity No 1159690. Charitable Incorporated Organisation 

Table 2 Comparison of muzzle energies for different types of commercially available handgun

ammunition

Cartridge/Calibre

Bullet/Shot 

weight

(grain (grams))

Muzzle velocity

(ms ̄1)

Muzzle energy

(Joules) measured

.32 S&W Long* 98 (6.35) 215 155 

.38 S&W 146 (9.46) 209 203 

.38 Short Colt 125 (8.10) 223 203 

.32 ACP 

Accles and Shelvoke

85 (5.51) 274 217 

.38 Long Colt 150 (9.72) 223 237 

.38 Special 158 (10.24) 230 271 

.38 Special + P 158 (10.24) 279 399 

.44 S&W Special 246 (15.94) 230 420 

*Ammunition used in a converted .310 Greener ‘Bell Gun’. The shaded area indicates the standard

ammunition loaded for the .32 Cash Humane Killer. Any ammunition generating a muzzle energy

significantly less than this is not recommended for the humane destruction of large animals.

Shotgun Ammunition

Shotgun charges differ from those used in free‐bullet weapons, in that the mass discharged

comprises a number of lead or steel balls (commonly known as ‘shot’), as opposed to a single, heavy

projectile. Shotgun cartridges differ according to their intended use, and the number, size and

weight of the individual shot differs according to the type of cartridge. In a standard 12 bore

cartridge, the total weight of the shot‐charge is normally 30g, whatever the size of the shot

contained within it. The range is: from 6 balls, each weighing 5g, in LG (buckshot); to 630 balls, each

weighing 0.05g, in No.9 shot. The most common cartridge in general use is No.6 shot, which in a 12

bore cartridge contains 287 balls, each weighing 0.1g.

In normal use, the shot cartridge is fired at a distant, moving target (up to 40m away). The shot

leaves the muzzle of the shotgun as a dense charge but quickly starts to separate and form a wide

‘pattern’ into which, it is intended, the target will fly or run. When a shotgun is discharged at very

close quarters to the subject, as is necessary for the humane destruction of livestock, the pattern

does not have time to start to develop before the shot‐charge impacts on the target. Therefore, the

shot effectively strikes as a solid mass at high velocity, with the resultant high kinetic energy which is

required to penetrate the skull and destroy the contents of the brain cavity. A comparison of the

muzzle energies of different sizes of shotgun cartridges is shown in Table 3.

   
© HSA 2016 Last updated 2014 

The Old School, Brewhouse Hill, Wheathampstead, Herts, AL4 8AN, UK 

t: +44(0)1582 831919 f: +44(0)1582 831414 e: info@hsa.org.uk w: www.hsa.org.uk 

Registered in England Charity No 1159690. Charitable Incorporated Organisation 

Table 3 Comparison of muzzle energies for shotgun ammunition

Model

Shot weight 

(grain (grams))

Muzzle velocity

(ms ̄1)

Muzzle energy

(Joules) calculated

12 bore 463 (30) 434 2,825 

16 bore 409 (26.5) 421 2,348 

20 bore 355 (23) 421 2,038 

28 bore 247 (16) 411 1,351 

.410 139 (9) 405 738 

Positioning

To result in an immediate kill, the bullet or shot‐charge must be administered to the correct part of

the skull. In most animals this is the frontal region of the head. The ideal sites and directions of

impact differ between species according to certain physical features. When a free bullet is used, the

bullet should ideally come to rest in the upper part of the spine; when a shotgun is used the pellets

should disperse within the cranium, completely destroying the brain.

Cattle

In cattle, the brain is situated high in the head. The ideal point of penetration is in the middle of the

forehead – at the crossing point of two imaginary lines drawn between the middle of each eye and

the centre of the base of the opposite horn. This should give a position about 7cm, ±1cm, above a

line drawn across the forehead at the back of the eyes. The shot should enter at right‐angles to the

skull (Figures 3 and 4).

Figure 3 Cattle shot 

position 

Figure 4 Commercial beast (2 years) 
© HSA 2016 Last updated 2014 

The Old School, Brewhouse Hill, Wheathampstead, Herts, AL4 8AN, UK 

t: +44(0)1582 831919 f: +44(0)1582 831414 e: info@hsa.org.uk w: www.hsa.org.uk 

Registered in England Charity No 1159690. Charitable Incorporated Organisation 

In calves the brain is relatively larger than in adult cattle, but the upper part is under‐developed. The

aiming point is slightly lower than for adult cattle, and the gun should be tilted back to obtain the

correct angle of incidence to destroy the brain stem (Figure 5).

Mature bulls may have a hard, thick frontal bone, often covered in dense, matted hair (Figure 6).

This combination can sometimes prove difficult to penetrate with small calibre projectiles and

therefore a shotgun is a better option. 

Figure 5 Infant calf (6 days) Figure 6 Mature bull (9 years) 

Deer		

The deer’s brain is situated high in the head. However, when shooting deer it must be remembered

that antlers do not equate to horns in cattle. The ideal aiming point is in the middle of the forehead,

at the crossing point of two imaginary lines drawn from the middle of each eye to the top of the

opposite ear (Figure 7). In stags, this spot is found between the antlers. As with cattle, the angle of

the shot should be directed through the brain stem (Figure 8).

Figure 7 Deer shot position Figure 8 Stag (2 years)
© HSA 2016 Last updated 2014 

The Old School, Brewhouse Hill, Wheathampstead, Herts, AL4 8AN, UK 

t: +44(0)1582 831919 f: +44(0)1582 831414 e: info@hsa.org.uk w: www.hsa.org.uk 

Registered in England Charity No 1159690. Charitable Incorporated Organisation 

Horses

In horses the brain is situated high in the head. The shot should be aimed in the middle of the

forehead, but slightly higher than the position for cattle. Take two imaginary lines drawn from the

middle of each eye to the base of the opposite ear; shoot the animal approximately 2cm above the

point where they cross (Figure 9). The muzzle of the firearm should be slightly tilted so that the shot

is directed through the cerebral cortex towards the brain stem (Figure 10). If a horse has been

sedated prior to shooting and is holding its head in a lower than normal position, care must be taken

to adjust the angle of the shot accordingly.

Figure 9 Horse shot position Figure 10 Colt (2 years)

Pigs		

Pigs are among the most difficult animals to shoot. There are two reasons for this: first, the target

area is very small and this problem can be exacerbated by the ‘dish’ (concave) face shape of certain

breeds and in aged pigs; second, the brain lies quite deep in the head, relative to other species, with

a mass of sinuses lying between the frontal bone and the brain cavity. The ideal site for shooting pigs

is one finger’s width above eye level, on the mid‐line of the forehead, aiming towards the tail

(Figures 11 and 12).

Figure 11 Pig shot position Figure 12 Bacon pig (6 months)
© HSA 2016 Last updated 2014 

The Old School, Brewhouse Hill, Wheathampstead, Herts, AL4 8AN, UK 

t: +44(0)1582 831919 f: +44(0)1582 831414 e: info@hsa.org.uk w: www.hsa.org.uk 

Registered in England Charity No 1159690. Charitable Incorporated Organisation 

Older pigs and exotic breeds, such as the Vietnamese Pot Bellied Pig, often have foreheads of thick

bone and this can cause problems when using free‐bullet humane killers, especially older .22 or .310

models. The bullet may become lodged in the sinuses and fail to penetrate the brain (Figures 13 and

14). Some older pigs, especially boars, may have a bony ridge running down the centre of the

forehead; in such cases the muzzle of the humane killer should be placed slightly to one side of the

ridge, aiming into the centre of the head. Because of the problems which might arise with adult pigs

and exotics, it is recommended that where possible, they are destroyed by use of a shotgun (12, 16

or 20 bore). If a shotgun is used, the target area is the same as that for the humane killer;

alternatively the animal can be shot through an eye, or from behind an ear, aiming toward the

middle of the head. When using a shotgun, the muzzle should always be held from 5‐25cm away

from the animal’s head. 

Figure 13 Adult sow (5 years) Figure 14 Vietnamese Pot 

Bellied (3 years)

Sheep and Goats		

When shooting sheep and goats, the aiming point is on the mid‐line, just above the eyes, directed

down the line of the spine into the bulk of the body (Figures 15 and 16). In practice this can be quite

difficult to achieve and a slight error in the angle of shot, or minor movement on the part of the

animal, can result in a free bullet exiting from the animal’s head or neck. In order to get this right

when using a free bullet weapon, the animal’s head must be in the normal position.
© HSA 2016 Last updated 2014 

The Old School, Brewhouse Hill, Wheathampstead, Herts, AL4 8AN, UK 

t: +44(0)1582 831919 f: +44(0)1582 831414 e: info@hsa.org.uk w: www.hsa.org.uk 

Registered in England Charity No 1159690. Charitable Incorporated Organisation 

Figure 15 Sheep and goat shot 

position

Figure 16 Ewe (4 years)

Heavily horned sheep and goats can present a problem if a free bullet weapon is used. The mass of

horn over the forehead can leave little or no target area: a shot between the eyes is too low and

should not be used under any circumstances. Such animals can be shot from behind the poll (Figures

17 and 18). However, this is dangerous with a free‐bullet weapon and, if undertaken, the animal

should always be situated on soft ground. Where possible, a shotgun is recommended for this type

of shot.

Figure 17 Heavily horned sheep 

and goats shot position

Figure 18 Billy goat (7 years)
© HSA 2016 Last updated 2014 

The Old School, Brewhouse Hill, Wheathampstead, Herts, AL4 8AN, UK 

t: +44(0)1582 831919 f: +44(0)1582 831414 e: info@hsa.org.uk w: www.hsa.org.uk 

Registered in England Charity No 1159690. Charitable Incorporated Organisation 

Operation		

When circumstances dictate that an animal should be killed, the person charged with carrying out

that killing is likely to have both legal and moral responsibilities with regard to animal welfare and

human safety. All animals which have to be killed for the purposes of routine slaughter or culling, or

in order to end their suffering, must be dispatched without causing additional pain or distress. The

circumstances in which animals require humane destruction can differ greatly; therefore different

procedures and methods need to be available to kill them. Whatever method is used, it is most

important that great care is taken by those involved not to cause any avoidable pain, suffering or

distress. Things are less likely to go wrong if the correct preparation has been carried out. Before

killing an animal the operator needs to ask the following questions:

• Does the animal need restraining? Is this possible? If so, which methods will cause the least

distress to the animal and the least danger to the operator?

• Is the animal securely confined, e.g. in a pen from which it cannot escape?

• In the case of a large animal, e.g. bovine, horse or pig, can the carcase easily be moved from

the spot where it will fall?

• What methods of killing are available? This may be a deciding factor in whether or not the

animal is moved to a more suitable spot.

Handling and Restraint

Animals should always be handled with great care. In many cases where animals have to be killed to

protect their welfare, the animals may well be recumbent or their movement limited by their injuries

or situation. However, there will be some animals which will require restraining in order to facilitate

safe and effective killing.  

The following methods of restraint are suggested: 

Pigs

Pass a rope around the upper jaw, behind the canine teeth. The pig will pull

away from the operator, who stands in front of the animal. This ensures that

the shot is being discharged directly away from the operator.

Sheep Use a halter, or confine the animal in a narrow pen constructed of hurdles or

gates.

Horses Control with a head collar and lead rope, halter or bridle.

Cattle Use a halter or confine the animal in a narrow pen constructed of hurdles or

gates.

Should there be any doubt in the mid of the operator as to the correct target area, then it should be

identified (see Positioning section) and, if possible, marked. This can be done using a spray marker, a

felt pen, or in the case of a very dark‐coated animal, French chalk.

Backdrop

When using a free‐bullet weapon, it is most important that a suitable backdrop is present in order to

stop the bullet, should it exit the carcase or should the target be missed. Suitable backdrops are

manure heaps, hay or straw stacks, earth banks, etc. Make sure there is no ‘dead ground’ (hidden

dips) between the target and the backdrop, from which people, vehicles or other animals may
© HSA 2016 Last updated 2014 

The Old School, Brewhouse Hill, Wheathampstead, Herts, AL4 8AN, UK 

t: +44(0)1582 831919 f: +44(0)1582 831414 e: info@hsa.org.uk w: www.hsa.org.uk 

Registered in England Charity No 1159690. Charitable Incorporated Organisation 

emerge. If no backdrop is present, the area behind the target must be clear of roads and dwellings to

a distance of 3,000m. A ricochet from a .32 humane killer bullet can travel in excess of 2,000m. All

people present must stand behind the operator, who should aim the shot down the spine and into

the body of the animal.

Exsanguination

Unless the carcase is to be used for human consumption, there is no necessity for it to be bled

following shooting with a free‐bullet weapon or shotgun. However, there may be profuse bleeding

from the gunshot wound and the nose and/or mouth, due to the physical damage caused by the

projectile. A thick, plastic bag can be placed over the head of the animal, immediately following

shooting, in order to prevent large quantities of blood accumulating on the ground and to protect

the sensibilities of any onlookers.

Checks

Having shot the animal, check that the shot has been effective. Look for an absence of rhythmic

breathing and an absence of corneal reflex. After a lapse of up to a minute, the animal may start to

twitch and, in some cases, convulse quite violently (especially pigs). This is normal in an animal

which has been shot correctly. The foremost sign of an ineffective shot is a return to normal

rhythmic breathing. This should not be confused with agonal breathing (occasional gasping), which is

of spinal origin and indicative of a dying brain.

When there are different weapons available, the choice should be based on the following criteria:

• The age and size of the animal

• The species of animal

• The location of the animal (e.g. in a built up area or rural open space with a suitable

backdrop behind the target)

• Accessibility of the target area

• Individual circumstances (e.g. on a solid floor or soft ground; inside or outside; road traffic

accident or racecourse casualty; emergency slaughter or routine culling)

• Presence and safety of onlookers

Carcase Disposal		

It is important that, when animals have been killed on‐farm or in other situations outside the

slaughterhouse, the carcases should be disposed of properly and promptly. Apart from the obvious

environmental, public health and disease implications, this is often also a legal requirement.

Therefore, in addition to complying with the necessary firearms legislation and undertaking training

to gain the skills required to kill animals humanely, the prospective operator should also have a

carcase disposal procedure in place before killing an animal. However, it is recognised that this may

not be possible in the case of an emergency. Also remember that if a large animal, a horse for

example, is killed in a confined space such as a stable, the carcase must be removed promptly. If left

for too long it will go into rigor mortis and will be difficult to remove.

Legislation regarding carcase disposal varies between countries. Operators should take care to

ensure that they comply with relevant local and national laws.
© HSA 2016 Last updated 2014 

The Old School, Brewhouse Hill, Wheathampstead, Herts, AL4 8AN, UK 

t: +44(0)1582 831919 f: +44(0)1582 831414 e: info@hsa.org.uk w: www.hsa.org.uk 

Registered in England Charity No 1159690. Charitable Incorporated Organisation 

Depending on the circumstances, the options for carcase disposal may include:

Transport to an abattoir, making sure to comply with any relevant food hygiene legislation

Collection by or delivery to a knackerman for disposal

Collection by or delivery to a licensed incinerator

Other options available for carcase disposal on‐farm include burial and incineration. Both options

may be subject to national legislation, check with your local authority before proceeding to dispose

of any carcases on‐farm using these methods.

Maintenance		

Any weapon used for the humane destruction of animals should be correctly maintained, cleaned

and oiled after use, even if has only discharged one shot.

Always follow the manufacturer's instructions.

The inside of the barrel should be thoroughly cleaned out and be free of any condensation. The

outside of the gun should be cleaned and then a thin film of oil applied all over, using an oily rag. A

drop of oil should be applied regularly to all moving parts, but avoid getting oil into the breech of

any weapon.

Every six months, regardless of whether or not the weapon has been used, it should be taken out,

inspected and thoroughly cleaned and lubricated. A logbook should be kept in the gun cabinet and,

every time a weapon is used and/or cleaned, the details should be recorded and dated (Table 4).

Similarly, a logbook should be kept in the ammunition cabinet and entries made for each type of

ammunition, to record when it is bought and when it is used (Table 5).

Table 4 Example of entries in a gun cabinet logbook

Date Details of weapon Details of 

operation

Signed

25.02.13 Cash .32 Humane

Killer 

Two cattle

destroyed at road

traffic accident. Two

shots fired. Gun

cleaned. 

J. Smith 

02.03.13 Cash .32 Humane

Killer 

Three ewes

destroyed at Mile

End Farm. Three

shots fired. Gun

cleaned. 

J. Smith 

06.03.13 Greener Bell Gun Horse destroyed for

Mrs Jones. One shot

fired. Gun cleaned. 

T. Bond 

07.03.13 Cash .32 Humane

Killer 

Gun overhauled,

cleaned and

returned to cabinet.

J. Smith 

 
© HSA 2016 Last updated 2014 

The Old School, Brewhouse Hill, Wheathampstead, Herts, AL4 8AN, UK 

t: +44(0)1582 831919 f: +44(0)1582 831414 e: info@hsa.org.uk w: www.hsa.org.uk 

Registered in England Charity No 1159690. Charitable Incorporated Organisation 

Table 5 Example of entries in an ammunition logbook

50 x .32 Humane Killer Ammunition, purchased 30.6.2012

Date Ammunition 

in stock

Ammunition 

used

Ammunition 

left in stock

Signed

25.02.13 50 2 48 J. Smith 

02.03.13 48 3 45 J. Smith 

Safety

All firearms are potentially lethal. It is essential that the safety and operating procedures recommended

by the manufacturer are precisely followed, and that all operators are properly trained in safe operation

and maintenance.  

Get instruction from an experienced operator before using any firearm

Refer to the manufacturer’s instructions for the correct loading procedure and the type of

ammunition

Do not under any circumstances attempt to handle or operate firearms before reading and fully

understanding the manufacturer’s instructions for the particular weapon being used.  

Safe Operation

• When receiving or handing over a firearm, always open the breech and make sure it is not

loaded. Confirm this with any other parties present by turning the breech towards them and

showing it as being empty before completing the transfer.

• During and on completion of the loading procedure, the muzzle of the weapon must at all

times be kept pointing away, and at a distance, from the operator’s or any other person’s

body.

• Once the weapon has been loaded, ensure that the safety catch is on until ready to shoot.

• When handling  any firearm, never allow it to point at any part of your body or at any other

person.

• Keep your finger off the trigger until you are actually aiming at the target and ready to

shoot.

• When shooting smaller animals, ensure (if possible) that the subject is standing on soft

ground and ensure that no part of your body (e.g. your foot) is underneath the animal.

• Rifles, shotguns and general‐purpose handguns should never be discharged with the muzzle

in direct contact with the target area. Such action could result in severe injury to, or the

death of, the operator.

• In the unlikely event of a misfire, do not open the breech of the weapon for at least 30

seconds. Sometimes, slow primer ignition will cause a ‘hang‐fire’ and the cartridge will go off

after a short pause.

• If there is any reason to suspect that a projectile is obstructing the barrel, immediately

unload the firearm and look through the bore. It is not sufficient the merely look into the
© HSA 2016 Last updated 2014 

The Old School, Brewhouse Hill, Wheathampstead, Herts, AL4 8AN, UK 

t: +44(0)1582 831919 f: +44(0)1582 831414 e: info@hsa.org.uk w: www.hsa.org.uk 

Registered in England Charity No 1159690. Charitable Incorporated Organisation 

breech: ammunition may be lodged some distance along the barrel where it cannot easily be

seen.

• Immediately report any faults in the operation of the equipment to the person responsible

for maintenance (if applicable) and take the weapon out of service until the fault has been

rectified.

Cleaning and Storage

• After each use, thoroughly clean the weapon before locking it away.

• Make sure that the weapon is unloaded before cleaning.

• When not in use, firearms and ammunition should be stored separately and locked away in

approved storage cabinets.

Do not attempt to carry out cleaning and maintenance until you have made sure that the firearm is

not loaded. Always lock firearms away immediately after use. Do not forget to secure the

ammunition in a different location.

General points on safety:

• Always treat all firearms and shotguns as if they are loaded

• Do not climb trees or step over fences with loaded firearms

• Never carry any firearm in your pocket, purse or waistband: always use a pistol case or

proper holster with a safety flap or strap

• Never pull a firearm towards you by the muzzle

• Never point any firearm, loaded or unloaded, at anything you do not intend to shoot

• Never leave a loaded firearm unattended or carry one in a vehicle

• Firearms and illness, alcohol or drugs do not mix