Weapon Types and Their Operation

Terrible confusion exists as to what is a pistol, revolver, self-loading pistol and automatic. This is very basic firearms nomenclature, but it is often wrongly applied. The use of the correct term is absolutely essential if any credibility is to be maintained.

This chapter attempts no more than to carefully explain the correct usage and, where they exist, alternatives which one might encounter.

1.2.1 Handguns

There are three basic types of handgun: single shot, revolving and self-loading pistols.

Such exotica as double-barrelled Howdah pistols, self-loading revolvers and self-loading pistols with revolving magazines can be ignored for the purposes of this chapter.

In English nomenclature, all handguns are pistols; some are single-shot pistols; others are revolving pistols, and the rest are self-loading pistols.

The Americans take a slightly more laid-back approach with the terminology using revolvers and pistols. Pistols are also referred to as semi-automatics.

The term automatic is often misused, and when applied to a pistol should be used with great care. Correctly used, the term signifies a weapon in which the action will continue to operate until the finger is removed from the trigger or the magazine is empty - hence 'automatic'.

A true self-loading pistol will, after firing, eject the spent cartridge case then reload a fresh round of ammunition into the chamber. To fire the fresh round, the pressure on the trigger has to be released and then re-applied.

A few true automatic pistols have been commercially manufactured. Examples are the Mauser Schnell-Feuer pistol and the Astra Mod 902. Fully automatic pistols have, however, never been a commercial success due to the near impossibility of controlling such a weapon under full automatic fire. Each shot causes the barrel to rise during recoil, and before the firer has time to reacquire the target within the sights, the next round has fired causing the barrel to rise even further. Even at close range, it is unusual for more than two shots to hit a man-sized target.

Single shot. The vast majority of single-shot pistols are 0.22" LR (long rifle) calibre and are intended for target use. Generally, the barrel is hinged to the frame with some locking mechanism to keep it in place during firing. On unlocking, the barrel swings down allowing the empty cartridge case to be removed and a fresh one to be inserted. Other types exist in which the barrel is firmly fixed to the frame and some form of breech block which either swings out, pulls back or slides down to expose the breech end of the barrel for loading/unloading.

Revolving pistol. In a revolving pistol, or revolver, the supply of ammunition is held in a cylinder at the rear of the barrel with each round having its own chamber. Cocking the hammer rotates the cylinder via a ratchet mechanism to bring a new round of ammunition in line with the barrel. Pulling the trigger then drops the hammer thus firing the round. This is the most simple type of revolving pistol mechanism and is called the single-action mode of operation. The earliest types of revolving pistol employed this type of mechanism. A prime example of a single-action revolver is the Colt Single Action Model of 1873.

The other type of revolving pistol mechanism is called double action. In this design, a long continuous pull on the trigger cocks the hammer, rotates the cylinder, then drops the hammer all in one operation. Most modern revolving pistols employ this type of mechanism with virtually all of them having the capability for single-action mode of operation as well.

In the past, very few self-cocking revolving pistols have also been manufactured. These have an action which, after firing a round, automatically rotates the cylinder and re-cocks the hammer. The most successful of this type was the Webley Fosberry. This type of weapon is, however, extremely rare and exists nowadays only as a collector's item.

Revolvers can be subgrouped into solid frame, where the frame is made from a single forging, and hinged frame, where the frame is hinged to tip either up or down for access to the cylinder. Access to the cylinder for loading or reloading in solid frame revolvers is generally accomplished by having the cylinder mounted on a crane which can be swung out from the frame (Figure 1.14). Some weapons also have the cylinder mounted on a removable axis pin which

Revolver Mechanism
Figure 1.14 Modern revolver mechanism.

when removed allows the cylinder to be completely removed from the frame for loading and unloading. This type of frame is more commonly encountered in cheaper weapons, generally of 0.22" calibre.

Of the two frame types, the solid frame is the most common, due to its inherent strength and ease of manufacture.

Self-loading pistol (slp). In this type of weapon, the ammunition is contained in a removable spring-loaded magazine housed within the grip frame. The barrel of the weapon is surrounded by a slide with an integral breech block which is kept into battery (i.e. when the face of the breech block is up tight against the breech end of the barrel in a position ready for firing), with the rear of the barrel by a strong spring. Pulling back the slide allows the topmost round of ammunition in the magazine to present itself to the rear of the barrel. On allowing the slide to move forward under spring pressure, the round is pushed from the magazine into the chamber of the barrel by the breech block. This action also cocks the trigger mechanism.

On pulling the trigger, the hammer drops and the round is fired, the bullet being pushed down the barrel by the expanding gases. These gases also exert an equal and opposite force on the cartridge case which forces the slide and breech block to the rear. This ejects the spent cartridge case through a port in the side, or occasionally top, of the slide. At the end of its rearward motion, the spring-loaded slide moves forward stripping a fresh round off the top of the magazine and feeding it into the rear of the barrel ready for firing (Figure 1.15).

Barrel

Locking: Lugs

Barrel

Locking: Lugs

Slide

Chamber 22lr

Trigger Bai Msgazme

Figure 1.15 Self loading pistol (Colt 1911A1model).

Slide

Filing Pin Hammer

Trigger Bai Msgazme

Figure 1.15 Self loading pistol (Colt 1911A1model).

As the action is only self-loading, the pressure on the trigger has to be removed and then re-applied before another round can be fired. To prevent the weapon from firing continuously, a part of the action, called a disconnecter, removes the trigger from contact with the rest of the mechanism. Releasing the trigger disengages the disconnecter allowing the trigger to re-engage with the mechanism so that the fresh round can be fired.

An action such as that described, where the slide is kept into battery with the barrel by spring action alone, is the simplest type of self-loading pistol mechanism. It is generally referred to as a blowback action and is only of any real use for lower- powered cartridges. If a blowback action were used for any of the more powerful calibres, the unsupported cartridge would, on exiting from the barrel, explode due to the tremendous pressures produced during firing. For all practical purposes, the most powerful round which can safely be fired in a blowback action weapon is a 0.380" ACP (9-mm Short) cartridge. Some blow-back action weapons, such as the Astra Model 400 and the Dreys 1910 Military Model, have been designed to fire more powerful cartridges by having massive recoil springs. They are, however, either very difficult to cock due to the strength of the recoil spring and generally require some method of disconnecting the spring during the cocking operation.

Once more powerful ammunition is used, some other mechanism has to be employed to ensure that the pressures produced fall to a safe level before the fired cartridge case exits from the barrel. This is accomplished via a l ocked breech or delayed blowback mechanism in which the barrel is locked to the breech block by some mechanical means during the instant of firing.

With this type of action, the rearward thrust of the cartridge case against the breech block causes the barrel and attached breech block to move backwards together. At some point on its rearward travel, designed such that the bullet has exited the barrel and the barrel pressures have fallen to acceptable levels, the barrel is stopped and unlocked from the breech block. The breech block and slide can then continue to the rear and in so doing eject the empty cartridge case. On its return journey into battery with the barrel, a fresh cartridge is loaded into the chamber and the mechanism is cocked ready to fire again.

The variety of locked-breech mechanisms is vast and outside the scope of this book. They range from the very simple Browning 'swinging link' and Luger 'toggle joint' to the more modern systems using high-pressure gas tapped from the barrel either to keep the breech locked or to operate the unlocking mechanism.

0 0

Responses

  • Haben
    What make of hand gun had a barrell that unlocked and pulled forward to expose cylinder for loading?
    8 years ago
  • gimja
    How to remove the cylinder from the crane on S&W model 10?
    7 years ago
  • veikko
    What the mecanisem of revolvar gun?
    2 years ago

Post a comment