|The Basics of Firearms and Ammunition||
|The Basics of Firearms and Ammunition||
Auto loading pistol
Auto loading pistol or automatic pistol make up the fourth category of handguns.The term automatic pistol is a misnomer as this form of pistol is an auto loader in which the trigger must be pulled for every shot fired.Regardless of the correct terminology,however,these weapons are invariably called automatics or just pistols.These pistols use the forces generated by the fired cartridge to operate the mechanism that extracts and ejects the empty cases,loads the fresh cartridge and returns the mechanism into position to fire the next round.The best commercial automatic pistol was produced in 1893 by Borchardt.This weapon was the predecessor of the Luger.
Auto loading - The cartridges are almost invariably stored in a removable magazine in the grip of the pistol.Some automatic pistols such as the Intratic Tec 9 and the Mauser M1896,have the magazine in front of the trigger guard.The Calico auto pistol uses a 50 or 1oo round helical feed magazine on the top rear of the frame.The term clip is often used synonymously with the term magazine,however,most people use the terms interchangeably.
There are 5 methods of operation of automatic pistols,blow-back,delayed or retarded blow-back,blow-forward,recoil and gas.Only two of these methods are currently in widespread use,blow-back and recoil.
In a blow-back action,the pressure of the gas produced by combustion of the powder forces on unlocked slide to the rear,thus,starting the cycle of extraction,ejection and reloading.
Heckler and Koch P7 pistols are blow-back operated pistols with a recoil breaking system that delays breech opening.On firing the gun,part of the propellant gas is directed through a small vent in the barrel ahead of the chamber into a cylinder beneath the barrel.A piston attached to the slide enters the front end of this cylinder.The gas entering the cylinder acts against the pistons such that as the slide begins to move rearward by virtue of the recoil pressure,the movement of the piston in the cylinder is resisted by the gas pressure,delaying the movement of the slide and delaying the opening of the breech.Another unusual feature of this weapon is that the firing pin is cocked by a squeeze cocker incorporated in the front of the grip.On grasping the grip,the fingers depress the squeeze cocker,automatically cocking the gun.If the pressure on the grip is released,the squeeze cocker goes forward unlocking the gun.P7 pistols have fluted firing chambers and polygonal rifling of the barrels.
In a recoil operated automatic pistol.the barrel of the slide are locked together at the moment of firing.As the bullet leaves the barrel,the rearward thrust of the propellant gas on the cartridge case starts the barrel and slide moving to the rear.After a short distance,the barrel is halted and the locking device is withdrawn from the slide.The slide then continues to the rear,ejecting the fired case and starting the reloading cycle.
Traditionally,automatic pistols have had at least one manually operated safety device.Manual safeties are thumb pieces or buttons that are mounted on either the slide or receiver.Customarily on the left side,they are now ambidextrous or reversible,putting on the safety locks the firing mechanism (hammer,striker and sometimes sear) and prevents the weapons from discharging.Less commonly,automatic pistol like the colt M1911 are equipped with grip safeties,movable pieces mounted in the grip which prevent connection between the trigger and the sear except when the pistol is held out by springs when at rest.Grasping the grip pushes the piece in and permits connection between the trigger and sear and thus firing of the weapon.
Many of the newer double-action automatic pistols have a thumb piece on either the slide or frame which externally resembles the usual safety lever but is in fact a decocking lever.It may be on the left side,ambidextrous or reversible.When this thumb piece is pushed down,the hammer falls.The weapon will not discharge,however,as the thumb piece locks the firing pin and/or rotates a steel surface between the hammer and the firing pin to prevent contact between the two.In some weapons,the decocking lever now functions as a safety and the weapon will not fire as long as this device is down.Other automatic pistols do not have any manual safety but only a decocking lever like Sig_Sauer,in such guns,depressing the thumb piece causes the hammer to drop,putting the gun on a double action mode but not putting on a safety.The glock pistols have neither a manually operated safety nor a decocking lever.
The Sig_Sauers,as well as most of the newer quality automatics are equipped with a firing pin safety (lock).This internal device locks the firing pin in place preventing forward movement and thus accidental discharge.In order to fire the weapon,the trigger must be pulled back in order to disengage this safety.
Some pistols have a device that tells whether the chamber contains a cartridge.This may be a protruding pin at the rear of the slide or just protrusion of the extractor.Some automatic pistols have slide or just protrusion of the extractor.Some automatic pistols have magazine safeties.This device prevents discharge of the weapon when the magazine has been removed from it.In some weapons,it is possible to deactivate or remove this device.
With the rare exceptions,currently manufactured revolvers do not have manually operated safety devices.This fact seems to have escaped British writers,who in their detective and action fiction always have their characters putting on and taking off the safety of their revolver.Although thumb safeties are not present on modern revolvers.Smith and Wesson did at one time manufacture a model with a grip safety.As regards derringers,they may or may not be equipped with a push button safety that blocks the fall of the hammer.
Preparing an automatic pistol to fire involves 2 steps.First,the loaded magazine is inserted into the grip.The slide is grasped,pulled rearward and released.A spring drives the slide forward,stripping a cartridge from the magazine and loading it into the firing chamber,the weapon is now cocked and ready to be fired.If the weapon has manually operated safety,the safety may now be applied and the weapon may be decocked using the decocking switch or by holding the hammer back (usually with the thumb),pressing the trigger and gradually lowering the hammer.In the case of weapons of older design (the colt M1911),to fire the gun after the hammer is lowered,the hammer must be manually recocked for the first shot.After the first shot,the operating mechanism of the automatic pistol automatically cocks the hammer.Most auto loading pistols automatically cocks the hammer.Most auto loading pistols are now equipped with a double action trigger that will cock and fire the first shot as a result of continuous pressure on the trigger.In these weapons,after the hammer is lowered,in order to fire,one must just pulls the trigger.After this,the weapon automatically cocks itself for each suceeding shot.Even in double action automatic pistols however,the slide must be pulled back initially to chamber a cartridge.
Some of the newer double action auto loading pistols are manufactured in a number of variations.Thus,they can be purchased double action only and with or without safety levers.Browning has a model,the BDM (browning double mode),that has a screw-slotted selector on the left side of the slide.Using it,the trigger and hammer can be set for conventional double/single action or double action only.
The colt model 2000 (now discontinued) had a sliding trigger;turning barrel system;polymer frame;slide latch;hammer-less striker and automatic internal striker block that is cleared only in the last fraction of trigger movement.It only fires in the double action mode.
Beretta manufactures auto loading pistols with a tip-up barrel for first round loading.In this weapon,a loaded magazine is placed in the grip.A latch is depressed on the side of the frame and the barrel tips up exposing the firing chamber.A cartridge can then be inserted directly into the firing chamber.The action is then closed and the weapon is now ready to fire.A round can also be chambered the traditional way by pulling back and releasing the slide.
Following its introduction into the U.S.,the glock pistol became involved in controversy when members of the media and some politicians contended it was a plastic gun that was not detectible by x-ray or metal detectors.This os of course non sense.While the gun does have a polymer frame,the slide,barrel and internal components are steel.Since then,a number of other pistols with polymer frames have been introduced.