Glossary

A boxlock holds its lockwork inside a housing, while a sidelock carries it on side plates.^{2, 3}

The flat projects forwards from the receiver at right angles to the standing breech, and the cocking arms and locking bolts lie beneath it.⁴

A back-bored barrel has a bore diameter greater than the standard specification.⁵

The flats fit against the top of the action bar.⁶

On Beretta’s 686 Silver Pigeon I, the selector sits on the safety tang and moves sideways.⁷

The finish gives some protection against rust.⁸ In Britain, bluing is also called blacking.⁹

The bore starts in front of the chamber, which holds the cartridge.^{10, 11}

The lockwork sits in a box-shaped housing, while a sidelock carries its mechanism on side plates.^{2, 3}

The firing pin passes through the face to strike the primer.^{12, 13}

Length of pull is measured to the centre of the butt and includes any buttplate or recoil pad.¹⁵

A shotgun cartridge holds a charge of pellets and may also contain wadding.¹⁶

The process gives a hard-wearing surface without making the whole receiver brittle, and it can leave mottled blue, green and brown colours.¹⁸

Cast-off sets the stock to the right to suit the right eye and shoulder, and cast-on sets it to the left.^{19, 20}

The nominal length of a shotgun chamber lets the crimp of the cartridge it was made for open fully on firing.²¹

The pattern gives a gripping surface and can carry decorative borders.²²

A removable tube changes the choke by fitting a different internal taper at the muzzle.²⁴

Interchangeable tubes with different internal tapers change the shot pattern.²⁴ Beretta’s Mobilchoke and Optima-Choke families differ in thread and dimensions and are not interchangeable.^{27, 25} Nor are Browning’s Standard Invector, Invector-Plus and Invector-DS tubes.²⁶

The construction, also called demi-bloc, can be recognised by the joint running lengthways through each lump.²⁸

Drop at the comb is how far the comb sits below a line extended back along the rib.³⁰

The right barrel carries the right halves of the lumps and the left barrel the left halves, and the two barrels are joined along their centre line.²⁸

Each trigger fires its own barrel; the term does not cover double set triggers.³¹

Drop may be measured at the comb or the heel, and British usage also calls it bend.³⁰

Selective ejectors throw out fired cases but only raise unfired cartridges, which are then removed by hand.³²

Bulino engraving cuts shallow pictorial designs directly into the steel by hand with a graver.³⁴

On a break-open gun, the extractor lifts the cartridges as the gun opens.³⁸

A break-open gun may have a separate firing pin set in the breech face, or a pin formed as part of an enclosed hammer.¹³

The cone joins the space the cartridge case needs to the narrower bore ahead of it.⁴⁰

A break-open gun comes apart into three main assemblies: the fore-end, the barrels, and the action with the buttstock.⁴¹

The iron carries the fore-end’s moving parts and turns around the action knuckle as the gun opens.⁴²

The gases unlock the breech bolt and complete extraction and ejection, and a gas piston takes their pressure from a port in the barrel.^{43, 44}

A 12-gauge bore has the diameter of a lead ball weighing one twelfth of a pound, and British usage also calls gauge ‘bore’.⁴⁵

On a long gun, the grip is the rear handhold on the stock, and it is also called the wrist.⁴⁶

A spring drives the hammer when the sear releases it.^{47, 48}

The measurement relates the closed breech to the surface inside the chamber on which the case seats.⁴⁹

Drop at the heel is how far the heel sits below a line extended back along the rib.³⁰

The steel pin runs across the front of the action, and both the pin and the hook that turns on it can wear.⁵¹

In Benelli’s system, recoil compresses a spring between the bolt head and the bolt body, and the spring then drives the bolt rearwards to extract and reload.⁵²

The measurement includes any buttplate or recoil pad, and Hallowell takes it from the front trigger on a double-trigger gun.¹⁵

The lugs may be part of the bolt itself or separate components, and AFTE also calls them bolt lugs.⁵³

The bolt stays at the rear while the barrel returns forwards, and the returning barrel then releases the bolt to feed the next cartridge.⁵⁴

The block is machined from one piece of steel, and the tubes are fitted into it separately before the ribs are attached.⁵⁵

A nitro-proof mark shows that the gun has passed an official test with nitro-based powder.⁵⁶

Reto Buehler applies successive coats by hand and says most oil finishes are based on linseed or tung oil.^{59, 60}

Browning’s Citori 725, for example, has its barrels stacked vertically and fires one barrel with each pull of its selective single trigger.⁶¹

The bulge helps the shooter hold the grip the same way each time.⁶²

It gives the trigger hand a generally vertical hold, unlike the line of a straight grip.⁶³

American practice measures pitch down from a wall, with the butt resting flat on the floor; English practice compares the length of pull at the heel, centre and toe.⁶⁵

A date read from proof-house marks need not match the date the gun was made.⁶⁶

London’s proof ammunition produces higher pressure than maximum service ammunition.⁶⁹

British marks distinguish definitive proof and nitro proof, and the rules also identify reproof and steel-shot proof.^{70, 71, 72, 73}

Ribs may be solid or ventilated, broad or narrow.⁷⁴

A safety mechanism does not replace responsible gun handling.⁷⁵

The name describes an enlarged knob at the tip of the fore-end.⁷⁶

The sear rests in a notch in the hammer, and pulling the trigger moves it out of the notch to release the hammer.⁴⁸

The mechanism then switches to the unfired barrel, which fires on the second pull.⁷⁷

The action extracts and ejects the fired case, loads a fresh cartridge from the magazine and cocks the firing mechanism.⁷⁸

On a double-trigger gun, each barrel has its own trigger.³¹

The hammer, sear and mainspring are mounted on the inside of each lock plate.³

The plates are set into the receiver and the wood behind it, making a boxlock look like a sidelock.⁸⁰

An inertia trigger uses recoil to switch to the next barrel, while a mechanical trigger switches when the trigger is released.⁸¹

Two machines throw targets across a semicircle, and shooters move between stations around the semicircle and at its front centre.⁸³

Each station presents a different target, meant to reproduce a live hunting situation.⁸⁵

Under the British 2006 Rules, this proof is marked STEEL SHOT with a fleur-de-lis.⁷³

Stocks are commonly made of walnut or other wood, but synthetic materials are also used.⁸⁶

AFTE calls a stock without a pistol grip a straight stock.⁸⁷

In British gun writing, striker also means firing pin.⁹⁰

English practice measures pitch by comparing the length of pull at the heel, the centre of the butt and the toe.⁶⁵

The lever sits above the breech, and pushing it sideways releases the barrels from the frame.⁹²

The targets rise as they travel away from the firing line.⁹³

On a cartridge firearm, the trigger releases the sear so that the hammer or firing pin can fall.⁹⁴

A Blitz action mounts its moving parts on the trigger plate and can be recognised from outside by its broader plate.⁹⁵

The pivots may project from the sides of the barrels or from inside the receiver.⁹⁶