Glossary of target shooting terms from A to J
(shooting terms K to Z)
as applying to
Marple
Rifle and Pistol Club (MRPC)
This glossary is of necessity not exhaustive, it concentrates mainly on
the terminology of those aspects of shooting practised by members of
Marple Rifle and Pistol Club (MRPC) within the UK, it
is not intended to be a complete work of reference. If you can think of any
items that should be included, please email your suggestions to:
enquiries
Where there is more than one way of spelling a term, the most
usual is given first, for example: fullbore, instead of full-bore, or Full Bore.
This page covers glossary terms from A to J (including numerical terms), for
terms from K to Z, take
the link.
.17 HMR ... Is a rimfire rifle cartridge developed by Littleman Mitchell in 2002. It was made by necking down a .22 Magnum case to take a .17 (4.5 mm) bullet. It is by rimfire standards a high velocity round, reaching figures in excess of 2600 fps with 19 grain bullets.
.177 (4.5 mm) ... The standard airgun calibre for international target shooting: Note that .22 airgun is not used at all for competitions shot to ISSF standards. Pellet diameter is nominally 4.5 mm, with a range of sizes in .01 mm steps to allow exact matching to specific guns for best accuracy. This is not a calibre for home bullet making as the necessary precision is too great to be achieved relatively cheaply.
.22 (Rimfire and Airgun) ... a) A rimfire cartridge calibre, much used in target shooting and often synonymous with the term, Small-bore. It is used in International competitions over both 25 and 50 metres outdoors and 25 metres indoors. Within the UK it is shot over 25 yards indoors and 100 yards outdoors. It can be shot with reasonable accuracy out to 200 yards, but beyond this distance most sights do not have enough vertical adjustment to allow for longer range shooting. This is not a reloadable round. Normal diameter is .224 inch with a 40 grain unjacketed lead bullet, but there are considerable minor variations between manufacturers, especially in firearm chamber dimensions. b) An airgun calibre, not used for international competition, but often used in the UK for vermin control. There is a wide range of pellets available in this calibre, so as to suit it to a broad range of applications, ranging from paper targets to small animals.
.22 Long ... An old round, not much used today. It has the case of the .22 Long Rifle but with a 29 grain bullet.
.22 Long Rifle ... The standard .22 rimfire cartridge for target rifle and pistol use. It can be loaded to supersonic muzzle velocities with light bullets, but for target shooting it is usually just subsonic with a 40 grain bullet.
.22 Short ... Only used these days as a target shooting round for timed fire pistol competitions. The case is shorter than the Long and it is fitted with a 29 grain bullet.
.223 (5.56 mm) ... The standard NATO small arms calibre, not used very much in the UK for long range outdoor target shooting. It is a centrefire cartridge and can be reloaded. Normal bullet diameter is .224 inch and weights range from 40 to 70 grain, with the heavier being favoured for long ranges.
.38/357 ... The most popular cartridge for reloading in the UK. The two dimensions are used to distinguish between the older, low powered .38 and the Smith & Wesson uploaded .357 Magnum, introduced in 1935. The .357 cartridge case is .135 inch longer than the .38 case so as to distinguish between the two. The nominal bullet diameter of both is .357 inch and the standard bullet weights are 148 or 158 grains.
4.5 mm ... The standard airgun calibre for international target shooting: see entry above for .177 for more details.
7.62 (or, 762 or, .308) ... 7.62 mm, or .308 inch is the NATO standard machine gun cartridge calibre and much used in the UK for fullbore rifle shooting outdoors at ranges up to 1200 yards. It is a centrefire cartridge and is often reloaded. It is a shortened version of the 30-06 cartridge, from which it has been developed since WWII. Bullets are .300 inch diameter and range from about 110 to 200 grains, with those in the 150-160 grain bracket being the most common.
9 mm ... A centrefire calibre, much used by the military in both handguns and sub-machine guns. Not much used in the past as a target round, as it is not easy to download and maintain functionality in semi-automatic guns. This is less of a problem today since the ban on such guns in the UK. Even so it does not have much of a following, due possibly to its relatively short range, even in carbines. The actual bullet diameter in Imperial units is .354 inch and normally the bullets, although a bit on the light side at 115 grains, can also be fired from .38/357 guns.
.41 Magnum ... A centrefire pistol calibre, not much used in the UK. It has a higher velocity than the .44 magnum with lighter recoil, it was introduced by Remington in 1964. Bullet diameter is .410 inch and typical weights are 180 or 200 grains.
.44 Magnum ... Introduced in 1956 by Remington, probably the most widely known high powered pistol cartridge, thanks to films such as "Dirty Harry". It is a centrefire cartridge, easily reloaded and accurate at quite long ranges (up to about 300 yards, especially in a carbine). Bullet diameter is .429 inch and an average weight is 240 grains.
.45 ACP ... ACP stands for, "Automatic Colt Pistol" and was made famous by the gun that fired it, the M1911 Colt self-loading pistol (and also the 'Tommy Gun', or Thompson Sub-Machine Gun). It is a centrefire cartridge which itself is quite accurate at short ranges (up to 100 yards), but was originally intended for military use rather than target shooting. It is not a 'Magnum' round. Bullet diameter is normally .451 inch and average weight 230 grains.
ACP ... Automatic Colt Pistol.
Accidental discharge (AD) ... Sometimes called an, 'unintentional discharge'. Any firing of a gun which is not deliberate.
Action ... The mechanism of a gun by which it is loaded, locked, fired and unloaded.
Aim ... The process of aligning the gun with the target, usually by means of the sights.
Aiming Mark ... That part of the target which is used to align the sights onto the target. Usually, but not always the aiming mark is a black disk in the centre of the target sheet.
Aiming picture ... The appearance of both sights and target when they are correctly aligned. See also, sighting picture.
Airgun ... A loose term applied to any rifle or pistol that uses some form of compressed gas as the propellant. Air rifles generating over 12 ft/lb of muzzle energy and Air Pistols over 6 ft/lb are classed as firearms and must be held on a Firearms Certificate in the UK.
Air resistance ... The slowing effect (or drag) on a projectile in flight, due to friction with the atmosphere.
Ammunition ... The name given to the 'fuel' used by all types of gun. It must be realised that 'bullet', 'round', 'cartridge', 'nature', 'pellet' and 'projectile' are all parts of the make-up of ammunition. See the individual entries below for more information.
Anti-splash Curtains ... Curtains made of a rubber compound (in the UK the material is often called by its trade name of, Linatex) and hung in front of the Bullet Catcher (see below) so as to stop any back-splash from the bullets when they break up on impact.
Aperture Sights ... The standard type of sights used on air rifles and .22 rifles for target shooting. The sights consist of a rear unit with a small hole in it which is used to centralise the eye. A fore sight containing a ring, in the centre of which the (round) aiming mark is placed.
"Are you ready"? ... The question asked of competitors in timed fire events just before the timing commences.
Automatic ... A somewhat misleading term used to describe a semi-automatic pistol. A semi automatic is a self-loading gun which fires one shot for each pull of the trigger. A full automatic is a machine gun, i.e. a gun which continues to fire once the trigger is pulled.
Ball ... Either a standard cylindrical bullet (see below) or literally a round ball which is often used in Black Powder guns, especially smoothbores.
Ballistic coefficient (BC) ... A measure of a given projectile's ability to overcome air resistance in flight when compared to a standard projectile used to calculate ballistic tables. The BC will always be less than 1 and the higher the number the better. For example a BC of .39 is better than one of .142, especially as the range increases.
Ballistics ... The study of what happens to a fired projectile. The study is divided into, internal, external and terminal ballistics. For target shooting purposes it is the first two which are important.
Barrel ... That part of a gun along which the bullet or pellet(s) travel when fired, it is usually but not always circular in cross-section.
Barrel length ... Normally this is the distance from the muzzle to the chamber and it includes the chamber itself. This measurement does not include accessories or barrel extensions like flash suppressers or muzzle brakes. The barrel length of a revolver is the distance from the muzzle to the breech end immediately in front of the cylinder, it does not include the cylinder itself.
BB ... 1) Round ball Airgun projectile of .175 inch diameter, much used in the USA for casual 'plinking' and seldom encountered in the UK. 2) A round shotgun cartridge projectile of .181 inch diameter.
BB Cap ... Bulleted Breech Cap, an almost obsolete .22 rimfire cartridge, usually powered by the primer alone and firing a very light bullet. It is physically much shorter than a .22 short rimfire round.
Bedding ... The manner in which the barrel and action of a long arm are fitted to the stock: the point(s) of contact in fact between the two.
Belted Case ... A rimless cartridge case with a raised integral belt around the case just ahead of the extractor groove to provide a positive headspace surface while retaining the extractor groove. This type of construction is usually used only on large capacity magnum rifle cartridges.
Bench Rest ... a) A form of shooting done with the gun supported in some way, either partly or wholly, on a 'bench' rather than solely by the marksman. Normally scored by measuring the size of a 5 shot group rather than the actual numerical value shot on the target. b) A device for testing the accuracy of guns and ammunition: see Machine Rest below.
Berdan ... A centrefire primer system developed by Hiram Berdan (an American) in 1858. It is characterised by having multiple flash holes and an integral anvil in the case. By one of those curiosities of fate, the Berdan system is used by the British armed forces and the Boxer system (by a Briton, Edward Boxer) by the Americans. Berdan cases are not as easy as Boxer cases to reload, due to the multiple, non central flash holes making removal of the fired primer more difficult: see below for Boxer.
Bigbore ... centrefire calibres larger than .22 rimfire. Generally taken as a synonym for fullbore: see below.
Bipod ... A twin legged support for a rifle, musket or carbine, usually fixed at the end of the stock away from the shooter and now illegal for competition use under ISSF rules.
Bisley ... The outdoor range located at Bisley, Surrey, England. It is the home range for both the NRA and the NSRA and has available distances of up to 1200 yards.
Black Powder or Black-Powder or Blackpowder (BP) ... Gunpowder used to operate muzzle loading guns. BP is classed in the UK as an explosive not a propellant and so an explosives licence , which is issued at no cost on application, is needed to both buy and store it. Although it is not normally called, 'smoky powder', it is notorious for the clouds of grey-white fog that it produces on being fired (the origin of the term, "The fog of war"). This can be a real problem on indoor ranges unless equipped with adequate ventilation. See the entry for smokeless powder below. The basic ingredients are saltpetre (potassium nitrate), charcoal (carbon) and sulphur: see Gunpowder below. As a matter of historical interest, Black Powder was used in the early metallic cartridges, both for rifle and pistol.
Blank ... A cartridge loaded without a bullet. On firing it produces the usual loud 'bang' but with little danger to life. Note a) 'Blanks' are not to be considered as being 'safe' as close to the body the blast of hot gas and wads from the muzzle are distinctly dangerous. Note b) Some blanks do in fact have a bullet, usually made of either wood, or more usually these days, wax. This is so that automatic and semi-automatic weapons can function normally when shooting such ammunition. These blanks can kill, especially at close range.
Blow-back ... The method of operating low-powered semi-automatic guns. The bolt is literally 'blown' open by the cartridge when the gun is fired. It is normally used for .22 rimfire ammunition only, as any more powerful cartridge would require either an excessively heavy bolt and / or a very strong spring to keep the breech sealed until the pressure had dropped to a safe level before opening the chamber.
Bluing ... An oxidation (rusting) process normally applied to firearm metal parts. It is controlled by applying oil (usually heated) which mixes with the nitrates used in the process. The oil prevents further rusting by sealing the metal. This gives the metal a blue/black colour. It is also possible to "brown" or "black" guns by a similar process.
Boat Tail ... The tapered rear end of some bullets, used to increase ballistic efficiency at long range by reducing atmospheric drag. So-called because in plan view the bullet outline resembles that of a boat.
Body twist ... The effect whereby the shooters body is twisted, or turned by the recoil forces when the gun is supported on one side of the body (such as a rifle held to one shoulder for support)
Bolt ... a) A steel rod-like assembly similar in design and operation to a normal door bolt, which moves back and forth in the action when operated by the shooter's hand. It seals the cartridge in the chamber during firing and extracts it afterwards. b) In automatic and semi-automatic repeating guns, it loads the rounds from the magazine and unloads the fired cases, it may only have a passing resemblance to a door bolt and may not necessarily be turned to lock or unlock.
Bolt Action ... A type of gun, usually, but not always a rifle, which is loaded and unloaded by means of a manually operated bolt. It can be either a single shot, or a multi shot gun.
Bore ... a) The interior diameter of the barrel of a firearm between the chamber and the muzzle. b) The British word for the calibre of a shotgun (in America they use 'Gauge'). A 12 bore shotgun has an internal barrel diameter of .729 inch and this is derived from the diameter of a lead ball of such size as 12 of them would weigh one pound.
Bore diameter ... In rifled arms, the diameter formed by the top of the lands, in smooth bores, the diameter of the barrel just ahead of the chamber.
Bore line ... An imaginary line projected from the muzzle of a gun along the centre of the bore.
Bottleneck Case
... Cartridge case with a neck diameter smaller than
its body diameter thus creating a shoulder
and giving the case the appearance of a wine bottle in profile.
Boxer
... A centrefire primer system developed by Edward Boxer (a Briton) in 1858. It
is characterised by having one central flash hole and the anvil as an integral
part of the primer. Very easy to reload and used by the American armed forces
and most home reloaders in the UK. See above for Berdan.
Brass ... 1) A term used to mean empty, reloadable cartridge cases. 2) An alloy of copper and zinc, the usual ratio for cartridges being, copper 70% and zinc 30%. 3) A Yorkshire dialect word for money.
Breech ... The end part of the barrel nearest the shooter with the chamber into which the cartridge or projectile is loaded.
Breech loader ... A firearm loaded through the breech end. Note that this does not automatically imply a gun firing metallic cartridge cases: see muzzle loader below.
Brisance ... In addition to strength, explosives display a second characteristic, which is their shattering effect or brisance (from the French meaning to "break"), which is distinguished from their total work capacity. This characteristic is of practical importance in determining the effectiveness of an explosion in fragmenting shells, bomb casings, grenades, and the like. The rapidity with which an explosive reaches its peak pressure is a measure of its brisance. This term is often misused to indicate a primer's ability to set-off the main charge in a metallic cartridge.
BSA ... Birmingham Small Arms (a firearms manufacturing company located in Birmingham, England).
Bull ... The centre of a target, usually scoring 10 when hit. There are targets with lower value centres, such as 5, or 7, which are used for specific competitions.
Bull Barrel
... A firearm built with an extra
thick-walled barrel that adds weight to the
gun and especially to the
muzzle end. It
thus reduces recoil and minimises
the effects caused by heating when firing rapidly.
Bullseye Bull's
Eye
... a) The centre of a target (see Bull above). b) A type of fast burning
smokeless powder
originally made by the American
Hercules Company (now
called,
Alliant Powder Company)
and particularly suited to cartridges intended to be shot by short barrelled
guns such as handguns.
Bullet ... The name given to the single, usually cylindrical projectile that comes out of the barrel of a gun. If there is more than one projectile, then usually the term used is 'pellet', as in a shotgun cartridge. Note: a) only the ignorant use terms such as, 'live bullets' or 'bullet heads'. b) only the ignorant use the term, 'bullets' when they mean either 'ammunition', or 'cartridges'. A bullet by itself is harmless, it is just a lump of metal and is not subject to any licensing conditions within the UK.
Bullet Catcher ... The part of the butts (see below) which actually stops and retains the fired bullet.
Bullet Mould ... A device of either steel or aluminium used to cast bullets for home reloading. The molten material (usually lead, or an alloy of lead) is poured into the mould and when set, the bullet can be removed and loaded to make a complete cartridge.
Bullet path ... The track or path taken by a bullet in flight. It is described by the position of the bullet as being above (+) or below (-) the line of sight at any given distance. Also known as the bullet trajectory.
Bullet puller ... A device used to 'pull' a bullet from its cartridge case. Normally, either a collet is clamped round the bullet and it is literally pulled from the case, or an inertia hammer is used, whereby the case is held and the bullet 'pulled' by its own inertia, when the tool is struck against a hard object.
Burning rate ... The relative speed at which a propellant powder burns in comparison to other powders in a controlled combustion chamber. A fast burning powder is used in short barrelled guns, such as pistols and a slow burning one in rifles, especially magnum guns with long barrels. It is potentially hazardous to use fast burning powders in long barrelled guns, because the pressure may rise to dangerous levels before the bullet exits the muzzle.
Butt ... The rear end of a rifle or shotgun stock (the part that rests against the shoulder). In a handgun, the bottom part of the grip.
Butt Plate ... The plate, usually of some rubber, or plastic compound that cushions the shooters shoulder from recoil when a long-arm is fired. It is fitted onto the end of the stock.
Butts ... The name given to that part of the range which contains the target frames and the bullet catcher which traps and safely contains the fired projectiles.
Calibre ... The diameter of a projectile, or the bore of a firearm. In rifled arms this measurement is from top of land to top of land across the bore diameter. This is not always quite what it seems, for example a .38 and a .357 calibre bullet are exactly the same diameter (the same bullet in fact). Quite often the name given to a particular gun, such as a .44 magnum, is a label or a name, not an actual measurement of calibre. In fact the actual diameter of a .44 magnum barrel is .429 inch.
Calling the shot ... The action of stating the position on the target of the last shot fired, before looking through the spotting scope, or retrieving the target. This is used as a training aid, so as to enable errors to be recognised.
Cannelure ... The circumferential groove or indentation in a cartridge case and / or bullet used to hold the projectile in place and prevent its rearward movement on loading, or whilst in the magazine during recoil.
Cant ... The angle of lean from the vertical that the firearm has whilst being held by the shooter.
Cap ... An explosive device fitted over the nipple of a percussion Black Powder gun in order to initiate ignition of the main charge and fire the bullet.
Capping off ... The process of firing a cap on its own before attempting to load a percussion fired Black Powder gun, in order to clear any oil or other residue from the nipple and chamber: see Flashing pans below.
Carbine ... Usually taken to be a shortened version of a long arm (see below), held in two hands and firing a pistol calibre cartridge.
Carbon Dioxide (CO2) ... Used as a propellant for 'air' guns. It is stored on the gun in liquid form under pressure and typically will give around 180 shots per fill from a purpose designed reservoir.
Card ... Another word for target.
Cartridge ... A complete round (see below) of ammunition (see above).
Cartridge Case ... The cylindrical case, usually of brass (but other metals such as steel and aluminium have been used) that holds the primer, main charge and bullet of a complete round of ammunition. The brass case is the most expensive part of a cartridge and in the instance of centrefire cartridges they can be reloaded.
Cast ... a) The type of bullet produced by a lead melting process. b) The process of making bullets for reloading by melting lead, or an alloy of lead. These bullets are normally not jacketed and so are only suitable for relatively low velocities. The process is quite suitable for home production. c) The lateral displacement of the centreline of the butt plate from the centreline of the bore. For a right-handed shooter when the centreline of the butt plate is to the left of the bore, it is expressed as cast-on and to the right as cast-off. The opposite is true for left-handed shooters. This is done to better align the shooters eye with the centre line of the bore.
Centrefire or Centre-Fire or centrefire... A cartridge ignited by a primer located in the centre of the case head. The system is suitable for reloading the cartridge case and is suited to high pressure ammunition. See also the entries for Berdan and Boxer.
Chain Fire ... This is what happens when a black powder revolver unintentionally fires several cylinders at once. It is caused by a flashover from the cylinder being fired, igniting adjacent unfired cylinders due to poor sealing of the chambers. In effect the gun fires more than one shot at the same time: this can be hazardous.
Chamber ... a) The part of a firearm containing the cartridge (or separate powder and ball) at the moment of firing it, normally at the opposite end of the barrel to the muzzle. b) The action of loading a round of ammunition into the gun.
Charge ... a) In the case of nitro powder and Black Powder, the amount, by weight, of the powder in a cartridge or load. b) In the case of Pyrodex, the amount, by volume, of the powder used. c) To fill a magazine with cartridges.
Cheek Piece ... A lateral projection from the comb of the stock. Provides additional support and contact to the shooter's cheek when the rifle is shouldered in the firing position. It is used to assist positioning the aiming eye correctly behind the sights.
Choke ... The restriction at the muzzle of a shotgun used to control the dispersion of the shot.
Chronograph ... A device to measure the velocity of projectiles fired from a gun or other device. Chronographs are essential equipment on ranges so as to be able to ensure that the velocity and energy limits of the range are not exceeded. Modern chronographs are electronic in operation and work by detecting the shadow of the bullet passing over a sensor and measuring the time before it passes over another sensor at a fixed distance behind the first. An inbuilt calculator then works out the velocity based on the simple formula of distance divided by time equals velocity. Most chronographs will record the maximum, minimum and average velocity of a group of shots and either display the results on a screen, or on a paper print-out.
Class, or Division ... The grouping into which competitors are placed according to ability, so as to allow for more even competition. Normally the classes run from, "X-Class", "A-Class", "B-Class" to "C-Class" in descending order of ability. Divisions follow the usual form of, "Division-1" to "Division-10" or as required in descending order.
Cleaning rod ... A rod, usually of plastic coated metal, longer than the barrel to be cleaned and often fitted with a ball-bearing handle. This rod takes a variety of cloths, or other attachments and pulls and pushes them through the barrel in order to clean it of any deposits.
Click ... The name given to the smallest adjustment of a sight, it is an onomatopoeic word.
Clip ... a) The name given to a (usually) metallic device to hold a group of cartridges together prior to loading them into the gun's magazine. b) An incorrect word used to describe a magazine and / or its contents.
Cock or Full-Cock ... To set the action (see above) into position for firing. On most muzzle loading firearms, the action has an intermediate position called half-cock (see below).
Comb ... The upper part of the stock where the shooter's cheek rests during aiming.
Compensator ... A muzzle brake, designed to reduce the felt effects of recoil by redirecting the escaping gases and to limit the muzzle jump on firing so as to assist rapid subsequent shots.
Cordite ... The trade name of one of the earliest smokeless propellants made in Britain, so called because of its long, cord-like appearance. It is not used today for smallarms, mainly because its high burning temperature leads to premature bore erosion.
Count back ... The system used to break a tie between two or more competitors with the same total score. It works by comparing the number of 10's shot by each person and the one with the highest number is awarded the higher ranking. If the competitors have an equal number of 10's, then the 9's are compared, then 8's etc, until the tie is broken.
Crimp ... The inward folding of a cartridge case used to retain the projectile (or shot charge in a shotgun). It can be either tapered, or rolled. Whilst a rolled crimp is more secure it cannot be used on cartridges such as the 9 mm, which headspace on the rim of the case mouth, as a rolled crimp would not provide a positive stop to the forward movement of the cartridge into the chamber.
Cross-ignition, or Chain-firing, or Flashover ... The term used to describe the dangerous possibility with a Black Powder revolver of multiple discharges when the primary cylinder is fired. This is as a result of the other cylinders being set off as a result of sparks from the primary cylinder igniting them when they are not lined up with the barrel. The original precaution was to put grease over the open ends of all cylinders as a sealant; the modern idea is to use impregnated felt wads as this is considerably less messy.
Crown ... The bevelled, countersunk, or rounded muzzle surface of a barrel, done thus to protect the point of exit from accidental damage.
C.U.P. ... Copper Units of Pressure. One of the standard methods of estimating the pressure inside a gun when it is being fired. Of great importance for safe reloading, as cartridge cases are quoted by their manufacturers as having a particular maximum c.u.p. which must not be exceeded.
Cylinder ... That part of a revolving firearm which holds the ammunition in individual chambers. The cylinder then rotates as the gun is used to present each round in turn to the barrel for firing.
Cylinder gap ... The gap between the front of the cylinder and the rear of the barrel of a revolver. This can be as small as 1/1000 of an inch in a high quality gun, but is usually nearer 1/100 of an inch. Some gas escapes as a result of the gap and bullet velocity is reduced, typically by about 5%.
Damascus ... An early method of making barrels out of welding together two or more rods of twisted iron and rolling them into a ribbon. This ribbon was then wrapped round a mandrel and hammered so that the edges became fused together. The result was a pretty patterned barrel of considerable aesthetic appeal and relatively little strength, for Black Powder use only and not to be used with nitro powder.
Density ... In the context of reloading this means, 'sectional density', or SD, which is the mass of a bullet in proportion to its cross-section. For simplicity the SD is usually calculated by dividing the weight (in grains) by the square of the diameter. As an example take a 150 grain bullet from a .308 Winchester: divide 150 by the square of .308 (.0949) to get 1581.2 and divide again by 7000 (the number of grains in a pound weight) to get .226 which is the SD.
Die ... A tool used in reloading metallic cartridge cases to resize the case to the specified dimensions, or a tool used to de-prime fired cases, or a tool used to seat bullets in cases, or a tool used to load powder into cases prior to seating the bullet.
Dioptre ... Refractive power of a lens. A lens having a focal length of one metre is said to have a power of one dioptre, a lens of 20 centimetre focal length has a power of +5 dioptres, one of 5 metres focal length has a power of +0.20 dioptres. The "+" sign indicates a converging lens, a "-" sign would indicate a diverging lens as is commonly seen in prescriptions for reading glasses.
Disconnector ... Mechanical device in a semi-automatic gun that is designed to prevent the firing of more than one shot from one pull of the trigger.
Division ... See, Class, above
Dominant Eye (and Hand) ... The stronger, or 'master' eye and hand. The dominant eye is the one through which a person would usually view an object when using a telescope. The dominant hand is what the shooter would describe himself as being: for example, 'right-handed'. This causes the shooter a problem when the dominant eye is on the other side of the body to the dominant hand. In about 15% of the population the dominant hand and eye are on opposite sides. This is much less of a problem for pistol shooters than anyone using a long arm.
Double Action ... The type of firearm action whereby one pull of the trigger performs the two separate functions of, a) cocking the gun and b) firing the gun. This term is often used to refer to revolvers, but it applies to all classes of firearm (see Single Action below).
Double-base ... Propellant powder in which nitro-cellulose is supplemented by nitro-glycerine.
Drag ... See air resistance above.
Drift ... 1) The lateral movement of a projectile due to rotation in flight through the atmosphere. If the gun has rifling with a left hand twist, the movement will be to left and vice versa. 2) The lateral movement of a projectile due to wind.
Drop ... a) The distance that a projectile falls at any given distance from the gun. b) The distance that the centre of the butt of a long-arm is below the centre line of the barrel. Both distances are measured in inches using the Imperial system.
Dry Fire ... Firing of an unloaded firearm to practice handling and shooting techniques. This can damage some types of actions, particularly rimfire unless a Dummy Cartridge, or Snap Cap (see below) is loaded to absorb the shock to the firing pin.
Dum-Dum ... Not a target shooting term, but mentioned for interest. It has become a slang word for any expanding bullet, especially one which has been modified by the end user and not manufactured that way. The term originated as a result of experiments done at Dum-Dum arsenal, India around 1898.
Dummy Cartridge ... Sometimes called, 'Drill rounds', these are cartridges assembled without either propellant or primer and use to test the functioning of guns and magazines without any danger of an accidental discharge. These special cartridges have to be indelibly marked to avoid fatal confusion.
Ears ... The name given to hearing protectors of whatever type.
Ears on ... The command by the Range Officer to put on hearing protection prior to commencing firing.
Ejector ... The mechanism which expels the cartridge or case from the breech of the gun. This is not the same as the Extractor (see below).
Elevation ... Vertical sight movement so as to raise (or lower) the point of impact on the target.
Equipment Control ... The person(s) who checks all shooting equipment and clothing before a shooter is allowed to take part in a competition, so as to ensure that it all complies with the current specifications. Normally the gun will be marked with a sticker to show that it has passed inspection.
Energy ... The force of a projectile at any given distance. The energy in ft/lbs. (foot-pounds) can be calculated from the weight of the projectile and its velocity. For example take a 150 grain bullet moving at 2800 fps (feet per second): Energy = (Bullet Mass x Velocity Squared) divided by 450,400 = 2611 ft/lbs. This formula is based on: k=½mv2 and includes allowing for converting bullet weight from grains to pounds and assumes that the acceleration due to gravity is 32.174 fps2.
English Match ... A 60 shot course of fire for .22 rimfire rifles shot from the prone position over 50 metres.
Eye Piece ... The lens of a telescopic sight nearest the shooters eye.
Eye Relief ... The distance that the shooters eye is positioned behind the ocular (eye) lens of a telescopic sight in order to obtain the best view of the target and to avoid a black-eye on firing. Somewhere between 2 to 4 inches is the usual distance.
Explosive ... Explosives are classified as low or high according to the detonating velocity or speed at which they change from being a solid or liquid to gas and other pertinent characteristics such as their shattering effect (or brisance). An arbitrary figure of 3300 fps is used to distinguish between burning / deflagration (low explosive) and detonation (high explosive). A propellant is said to burn at less than the speed of sound (approximately 1100 fps). Within the UK the possession and use of any explosive is subject to having the necessary licence.
Extractor ... The device which extracts, or removes the cartridge or cartridge case from the chamber of the gun. This is not the same as the Ejector (see above).
Eye relief ... The distance, usually between 3 - 4 inches, from the shooter's eye to the rearmost part of the sights. This distance is important both for good vision of the target and to prevent injury when shooting a gun with significant recoil. In the case of Telescopic Sights there are special models available for use with hand guns which have extended eye relief, so as to allow their use at about 18 inches from the eye.
Feinwekbau ... A popular German make of guns, especially air rifle and air pistol models. The name translates literally as: "Fine work company".
Felt recoil ... The way that a shooter actually feels the recoil, or 'kick' of a gun when it is fired. In general, guns firing ammunition with a nitro powder will have a sharper, more jarring recoil that those firing Black Powder. Guns with some form of automatic, or semi-automatic loading mechanism feel less harsh than those without, due to the operation of the gun 'spreading' the recoil out over a longer time period.
Felt Wad ... Currently the preferred method of sealing the open ends of black powder revolver cylinders is to use felt wads. These wads make far less mess, especially on indoor ranges than the older method of using grease or some other paste-type sealer.
Fg, FFg, FFFg, FFFFg ... Grades of size of Black Powder particles, from coarsest to finest. The "F" stands for "Fine" and the "g" stands for "grain", so FFg should have particles half the size of Fg, etc. FFFFg is mainly used as a priming powder for flintlocks, wheel locks and matchlocks. Also see 'Swiss' below.
Field Target ... A shooting discipline shot outdoors using sub-12 ft/lb air rifles from various positions. Normally the guns used are .22 calibre and the targets are the metal knock-over type. Scoring is different to that used for paper targets, as a target is either knocked over, or it is not, so there is no scoring a "7" for example, it is all either a "10" or a "0".
Filler ... Filler is any kind of inert substance, such as semolina, which is used to fill chamber / cartridge space in black powder guns, so as to allow the black powder to be compressed properly when using light loads.
Firearm ... Any gun which uses the combustion of a propellant or an explosive to discharge a projectile.
Firearms Certificate (FAC) ... The necessary permit to hold any firearm or ammunition in the UK, it lasts for 5 years before renewal, a simpler form of licence is required for shotguns. FAC are in different Sections and the type of guns used in target shooting are all in Section 1. Other Sections cover the whole range of firearms, for example machine guns are in Section 5 and historic breech-loading guns are in Section 7.
Fireform ... The process of changing the shape (and volume) of a cartridge case by firing with (normally) a light load in the gun in which it is to be used. This is a means of improving accuracy and functioning by matching the case to the exact size of the chamber of a particular gun.
Firing Pin ... The part of a gun's action which actually strikes the primer so as to set it off and initiate firing the cartridge's main charge of propellant.
Firing Point ... The physical position from which shooting takes place, they should be numbered consecutively from 1 upwards with contrasting colours i.e. if 1 is painted black, 2 should be white, etc.
Fixed Sights
... Non-adjustable sights, not used
for serious target work.
Flash Hole
... 1) The small diameter hole through which the 'flash' from the priming charge
of a muzzle loading gun travels to ignite the main charge
of black powder. 2) The small diameter hole (Boxer:
see above) or holes (Berdan: see above) through
which the flame from the primer of a centrefire cartridge passes to ignite the
main charge (usually of smokeless propellant) in the
cartridge case.
Flashing Pans ... The action before the commencement of shooting, of firing off a priming charge of powder from the pan of a matchlock, wheel lock or flintlock muzzle loading gun in order to clear any oil or other residue from the flash hole and chamber, before loading the main charge: see Capping off above.
Flash in the pan ... a) What happens when the priming powder in the pan of a matchlock, wheel lock or flintlock gun goes off without igniting the main charge. b) A short-lived enterprise of some sort.
Flinch or Flinching ... The involuntary physical reaction by the shooter to the firing of the gun. This movement spoils the accuracy of the shot and can be a difficult problem to cure.
Flintlock ... A muzzle loading firearm with its powder charge ignited by a flint striking a metal surface (the frizzen) to produce sparks which ignite fine priming powder, which in turn sets off the main charge.
Flyer ... A shot well outside the normal group on a target and not representative of the rifle or the cartridge's potential accuracy, almost always due to shooter error.
Fog of War ... The name given to the smoke produced on firing Black Powder weapons, this could be a serious problem in the Napoleonic era and could definitely hamper observation on the field of battle, for an example see the photo of a Colt Walker revolver being fired. It can also be a problem on indoor target ranges unless sufficient attention is paid to ventilation.
Follow-through ... Staying in the same position after pulling the trigger, or continuing the swing when firing at a moving target. This is done in order to assist in, 'calling the shot' (see above).
Foot-pound ... The energy required to lift one pound through a distance of one foot (strictly speaking this is only true at the earth's surface).
Forcing Cone ... The tapered section of a shotgun or revolver barrel where the pellets or bullet is guided into the bore.
Fouling ... The deposits that build up in the barrel of a gun after it is fired. Fouling can either be soft and harmless carbon residue, or more persistent lead or copper, both of which are detrimental to accuracy.
Fouling Shot ... The process of firing a shot off before starting trying to shoot accurately, so as to remove any oil from the barrel and to coat the bore with a layer of powder residue. This process is most important for muzzle loading guns in order to obtain consistent accuracy.
f.p.s. (or, fps) ... Feet per second, the standard measure of projectile velocity in the Imperial measurement system.
Free Bore ... The unrifled portion of the bore, if any, in front of the chamber, it can be up to about a half the length of the barrel. Not much used these days and normally only for low-powered cartridges such as the .22 rimfire.
Free Pistol ... A .22 calibre target pistol which is 'free' of most constraints as to barrel length, sight radius, weight etc.
Free Rifle ... A .22 or centrefire rifle which is 'free' of most constraints in the same way as a free pistol.
Frizzen ... The upright steel plate in a flintlock gun which is struck by the flint in order to produce the sparks for igniting the priming powder. Note: the sparks come from the steel NOT the flint!
Ft.-lb, or ft/lb ... Foot-pound, the standard unit of energy in the Imperial measurement system, used as a measure of the energy contained in a bullet in flight.
Fullbore or Fullbore or Full Bore ... Generally taken to mean centrefire calibres, especially those of .22 and greater: synonymous with the term Bigbore: see above.
Full-Cock ... The action of setting the action (see above) into the ready to fire position. See half-cock and cock.
Full Metal Jacket ... A jacket, usually of copper completely covering a bullet, so as to leave no lead exposed. Much used for military ammunition as it helps to comply with the Geneva Convention on Land Warfare, which specifies that expanding ammunition must not be used against human targets. It also allows the bullet to be driven up the barrel much faster than a plain lead projectile.
Gain twist ... A system of rifling with the pitch increasing towards the muzzle.
Gas cutting ... What happens when using high pressure cartridges in a revolver and the gasses literally cut the metal of the top strap of the frame when they escape through the cylinder / barrel gap.
Gauge ... a) A plug device used to accurately score a shot target, it has a diameter exactly that of the calibre used and when inserted into the target shows the edge nearest to, or in some cases, farthest from, the centre. b) In American usage it is the bore, or calibre of a shotgun or other smoothbore gun.
Grain ... a) A unit of weight used to measure powder charges and bullets. By definition it is 1/437.5 of an ounce avoirdupois and therefore there are 7000 grains to the pound. b) The natural pattern of wood.
Grease ... Grease used to be the preferred method of applying a flash-proof seal over the ends of black powder revolvers. Due to the mess grease makes on indoor ranges, it has been largely superseded by felt wads.
Greenhill's Formula ... An empirical formula that relates bullet weight and length to rifling twist. One must bear in mind that the formula assumes cylindrical pure lead bullets and doesn't work as well for small calibres as it does for large ones. Twist in inches (T) = [150/(L/D)]xD where L = bullet length in inches and D = bullet diameter in inches. It is best regarded as a starting point when determining rifling twist rates and not as an exact measure. See, Rate-Of-Twist below.
Groove ... The sunken part of rifling.
Groove diameter ... The distance across the bore of a rifled barrel from the bottom of one groove to the bottom of the one opposite, this is easily measured by means of a lead slug. In the case of a barrel with an odd number of grooves this is measured by driving a soft lead slug into the barrel and then measuring the slug's diameter over a land-to-groove cross section and then subtracting the bore diameter. The next step is to double this figure and add it to the bore diameter to get the groove diameter.
Group ... The pattern of shots on a target.
Group Size ... It is the distance between the centres of the two farthest apart shots in a group. The easiest way to measure this, is to measure from the outside edge of one bullet hole to the inside edge of the one farthest away. Another method is to measure the distance from outside edge to outside edge of the farthest apart holes and then subtract the bullet hole diameter.
Guncotton ... Nitro-cellulose: a form of smokeless propellant.
Gunpowder ... An explosive made up of 75% saltpetre, 15% sulphur and 10% charcoal. It has been used as both an explosive for blasting and mining operations as well as to fire projectiles from firearms. Also known as, Black Powder: see above
Half-Cock ... a) The safety position for a matchlock, wheel lock, flintlock or percussion gun. The hammer is moved to a halfway position from which it cannot be released by the trigger and the gun can then be carried loaded in safety. b) "To go off at half-cock" means to start an abortive, or failure-ridden enterprise and it is derived from the unfortunate practice of early guns to slip off the half-cock position and fire prematurely. See, cock and full-cock above.
Hammer ... a) The part of the action which drives the firing pin to strike the primer in a cartridge gun. b) the part of the action which carries the flint for a Flintlock gun. c) The part of the action which strikes the cap in a Percussion gun: see Serpent below for Matchlock guns.
Handload(ing) ... The practice of loading and reloading centrefire cartridges to either save money and / or produce specific cartridge characteristics; for example low velocity, minimum recoil rounds for rapid-fire target shooting. This is most easily done using Boxer primed centrefire cases: see Boxer above.
Hang fire ... A term applied to an excessive delay in ignition of the main charge after the primer has fired, this is mainly a problem for Black Powder muzzle loaders and especially Matchlocks.
Hard hitting ... A nonsense term used by the ignorant when describing guns so as to show how little they know or understand about shooting in general.
Headspace ... This is the distance from the breech face to that part of the chamber which stops the forward movement of the cartridge case. Different cartridge designs obtain their headspace in different ways. A rimmed case, such as a .22 rimfire uses the case rim to position the cartridge within the chamber, whilst a rimless cartridge, like the 9 mm Parabellum uses the rim of the case mouth, seating on an annulus in the chamber (this means that 9 mm cases must be both of exact length and not use a rolled crimp to hold the bullet in place).
Headstamp ... The manufacturers marks stamped into the primer end of a metallic cartridge case giving various details of its construction, such as calibre, maker, load, date of manufacture, etc. There is no universal standard for this information and its value and content can vary widely.
Idiomatic expressions ... There are several idiomatic expressions derived from shooting which have found their way into general usage, they include: A Flash in the Pan, Lock Stock and Barrel, Six Shooter, Bulls eye, To go off at Half-Cock, Dum-Dum and (from the Stanley Kubrick film) Full Metal Jacket. Definitions for all of these terms are to be found in this Glossary.
Inertia Firing Pin ... A firing pin which is shorter than the guide in which it travels to strike the primer. If it is propelled sufficiently quickly from its resting position, then it can contain enough energy to detonate the primer due simply to its own inertia.
Inertia puller ... See bullet puller above.
Inner-10 ... The name given to a smaller ring enclosed by the 10 ring on a target. Normally the Inner-10 does not have a score value, it is used as a tie-breaker between competitors with an identical numerical score; the one with the higher number of Inner-10's being the winner: see below for X-Ring.
International Shooting Union (ISU) ... See UIT and ISSF below.
International Shooting Sport Federation (ISSF) ... The successor to the UIT / ISU, it is the regulatory body (based in Munich) that controls all international target shooting with Airgun, Crossbow, .22 rimfire and centrefire, both rifle and pistol. All the rules and regulations concerning target shooting can be downloaded from their website in both English and German, but be warned that they are of a large file size (about 10 megabytes in PDF format). The rules for shooting are revised and re-issued in the January following the Olympics, so as to give all competitors the maximum amount of time to prepare for the next event.
Inward gauging ... The scoring process whereby the edge of the bullet hole nearest the centre of the target determines its value. In this method the shot hole has only to touch (not cut) the next higher scoring ring to be awarded the higher value: see also, Outward gauging and muzzle-loading gauging below.
Iron Sights ... See Metallic sights below.
Jacket ... A covering over the lead core of a bullet. Usually this cover is made of copper and can be either complete (see Full Metal Jacket above), or partial. If partial, it can leave either the nose or the tail of the bullet exposed. An exposed nose is much used in hunting, as it allows the bullet to expand and transfer more of its energy to the game being shot. All jackets allow the bullet to be fired with greater velocity than plain lead could withstand.
Journee's Formula ... The empirical formula used to calculate safe distances for shotgun pellets. It says that the maximum range in yards for a round pellet is 2200 times its diameter in inches.
Revised: 20-Apr-2022.