How it Works - "Watch and Shoot!" Quiz

Answer: Barrel

The barrel is the metal tube down which the bullet travels immediately after a round is fired. At the one end is the breech, a specially shaped chamber into which the ammunition is inserted and at the other end is the muzzle which can be fitted with a component known as a flash suppressor. Flash suppressors are generally fitted to military weapons and perform two roles; firstly to help reduce the amount of recoil that the shooter experiences and will reduce the amount of muzzle blast produced. Many barrels, on both military and civilian weapons, can also fitted with a bipod; a component consisting of two short, adjustable legs that are mounted towards the muzzle to assist the shooter in keeping the weapon stable whilst firing is taking place.

Answer: Hammer

This component performs a critical function as a part of the trigger assembly. The sear, which is a type of lever, is a notched bar which engages with the hammer and prevents it from striking the firing pin until the trigger is operated. In a semi-automatic weapon the sear works in conjunction with another component called the disconnector which prevents the sear from restraining the hammer whilst the trigger is depressed. Once the trigger is released the disconnector allows the sear to re-engage with the hammer, holding it in place until the trigger is squeezed again.

The design and tolerances machined into the sear have a direct bearing on the amount of pressure required on the trigger to initiate firing. In a handgun, a pressure of around five pounds is desirable for safety purposes; pressures reduced to around three and a half pounds or less could be considered to be dangerous.

Answer: Safety

There are a considerable number of different types of safety mechanisms in use today. Many revolvers make use of a 'half -cock' safety; when the hammer was positioned at its halfway point, it mechanically locked the trigger and was supposed to prevent discharge of a round should the weapon be dropped. This is better than nothing but I wouldn't want to take a chance testing it for real. My first revolvers, a Colt Diamondback and a Smith and Wesson Model 29 (both double-action revolvers), utilised a half-cock safety. Many modern automatics use what is known as a grip safety. Handguns with a grip safety require some pressure from the user to release the safety mechanism in order to fire.

The Browning Hi-Power 9mm automatic that was in use with the British Army during my period of service used a safety mechanism known as a magazine disconnect. In this small arm the removal of the magazine prevented the trigger and hammer operation even with a round in the chamber. Rifles and machine guns use a wide range of safety mechanisms which prevent the trigger being operated. The best rifle I ever owned, a US M1 Garand, used a rocking lever located in front of the trigger guard which prevented trigger operation.

Answer: Furniture

On military issued weapons the furniture - the butt or stock, the pistol grip and the front hand guard - are purely functional and as such are made of robust and very hardwearing materials. On civilian weapons however, the furniture is often seen as decorative as well as functional and can be encountered made from far more expensive and exotic materials. Should you ever get the opportunity, compare the workmanlike, oiled wooden furniture fitted to rifles such as the FN FAL or the Garand to that which you might find on a top of the line Wetherby rifle or a fine handmade English shotgun!

Answer: Selector switch

This is a component fundamentally related to the sear. Many selector mechanisms also incorporate the safety assemblies as in the US M16 rifle which has a three position selector; 'safe', 'semi' and 'auto' with some versions having the word 'burst' engraved on the receiver in place of 'auto'. Additionally, many modern small arms have an option to select a short burst of around three to five rounds.

The selector usually consists of a small lever fixed at ninety degrees to a shaft which passes into the receiver and through the trigger mechanism.

The shaft is fitted with a number of cam-like projections that engage and disengage with the sear as the small arm goes through its firing cycle.

Answer: Magazine

The magazine may be found in any one of a number of forms. Most commonly found today is the detachable box type which is often available in 10 and 20 round capacities for civilian weapons and in 20 or 30 for military types. Magazines can be internal, such as the clip loaded magazine on the US M1 Garand rifle, the detachable box types already mentioned which can be spring loaded, gravity fed such as the British Bren types or large drum types that may have a clockwork mechanism to ensure a steady rate of feed with capacities up to two hundred rounds! Magazines can also be found in use on belt-fed small arms such as the British General Purpose Machine Gun, the GPMG, and the FN Minimi support weapon.

Answer: Sights

Fitted as standard to all weapons, the sights are critical if you want to be able to hit the target! The most common type of sights encountered comprises a retractable leaf at the rear and a thin blade at the front mounted toward the end of the barrel. On the rear leaf type sight, the actual leaf itself lies flat against its housing until it is required. On the FN FAL, the block into which the rear leaf is fitted slides forwards and backwards on a graduated plinth marked with ranges from 300 yards to 600 yards which is the effective range of this and most other battle rifles. On some rifles such as the Heckler & Koch G3 rifle, the rear sight takes the form of a rotating drum. On both the FAL and the G3 the foresight blade, which is vertically adjustable, sits immediately above the barrel where it is joined by the gas piston rod assembly. For accuracy, the greatest distance that the designers can achieve between the two sight assemblies will have a beneficial effect.

Answer: Bolt

This part of a weapon is usually referred to as being one of two basic types; open or closed bolt. All bolt action rifles are of the closed bolt variety which means that, immediately before firing, the ammunition is enclosed within the chamber with the face of the bolt resting against the base of the ammunition case. Most modern semi-automatic rifles are also of the closed bolt type whereas fully automatics and many sub-machine guns will be of the open bolt type; on open bolt weapons the firing pins are fixed in nature and as the bolt moves forward and picks up the next round from the magazine, the round is fired before the it is fully seated in the chamber.

This is known as a 'blowback' weapon. In closed bolt weapons the round is fully seated in the chamber before the shooter pulls the trigger.

These weapons are usually of a type known as gas operated. Each type has its own advantages and disadvantages; open bolt weapons tend to be a little less safe in general use whereas closed bolt weapons can suffer from what are known as 'cook-offs' in which an excessively hot chamber can cause the round within to be initiated prematurely.

Answer: Piston and return spring

As the bullet is propelled up the barrel by the gases expanding behind it, some of this gas is bled off through small ports and passes into a small diameter tube often mounted above the barrel. This tube contains a long metal piston rod surrounded by a spring which is forced back against the bolt carrier or slide. Once the gas pressure inside the barrel has fallen to safe levels the bolt is unlocked and slides to the rear, removing the empty cartridge case as it does so.

At the end of this cycle, the slide begins to move forward again under pressure from the mainspring, collects a fresh round from the magazine and inserts it into the chamber in readiness for the cycle to begin again.

Answer: Extractor

The extractor is a small claw-like component mounted at the face of the bolt assembly that grips the base of the cartridge. After firing and as the bolt unlocks from the chamber the spent case is pulled from within and moving to the rear passes over another small tooth-like component called the ejector.

As the empty case passes over the ejector it is released by the extractor and jettisoned safely to the side of the weapon... Unless, of course, you were left-handed and using a version of the FN FAL such as the British L1A1. Unlike many modern small arms with reversible components made specifically for left-handed shooters, the British L1A1 was only made to suit right handed shooters; this invariably meant that a 'leftie' would often get hit in the face by an ejected casing!