Saturday, February 26, 2011

What are the differences between AK-47, AKM, AK-56, AK-74 and AK-101?

The AK family of assault rifles are pretty widespread around the world, because of their lower cost of manufacturing, lower tooling costs, general reliability under rough conditions and the fact that the former Soviet Union were pretty much handing them out like candy for years. Clones of the original AK design have also been manufactured by other countries: China, Bulgaria, Romania, even companies in the good ol' USA. Unfortunately, the media keeps referring to just about any assault rifle in the AK family as the "AK-47". This post aims to point out some members of the AK family and some of their major differences.

The AK is a Russian abbreviation for Avtomat Kalashnikova. The name Kalashnikova comes from the fact that its inventor is Mikhail Kalashnikov. The original development for this rifle started in 1945 and a prototype (the AK-46) was submitted for evaluation in 1946, but it was only in 1947 that it was cleared for production for use by select Soviet forces. There have been several improvements to the original design over the years and there are now many models in the AK family. With that little bit of history said, let's now study some of the key features of some models.

AK-47: This is the original version that was approved for use by the Soviets. It fires a 7.62x39 mm. cartridge. It was originally approved for some Soviet forces in 1947, which is why the name has 47 after it. During 1948-1951, it went into general production to be used by other Soviet military units as well (the Type-1 model). In 1952, the Type-2 version was introduced, which had a chrome plated barrel and receiver to resist corrosion and wear. The Soviets had originally tried to make the receiver out of stamped sheet metal, but didn't have the technology then to produce the part reliably. After a large number of rejections of faulty receivers, the Soviets opted to use a receiver made of forged steel, which was milled into the final shape using various machining operations. This made the overall production rate slower.

AK-47 Type 2 variant. Click on image to enlarge. Public domain image.

AKM: This is a popular variant of the AK family. This was created as an improvement of the original AK-47 design. The letter M in the name "AKM" stands for Modernizirovanniy, which is the Russian word for "modernized." The AKM design was developed in the 1950s and finally was approved for full production in 1959. It fires the same 7.62x39 mm as the AK-47 for backward compatibility. However, the design was much revised and enhanced from the original AK-47 to allow it to be mass-produced. The Soviets acquired modern mass production technologies from captured German engineers (including Hugo Schmeisser, the designer of the StG-44) and used those on the AKM. Among some of its improvements:
  • Replacement of the milled receiver with a receiver made out of stamped sheet steel. Machining is a lot slower process than using a press to stamp parts. Hence, use of stamped parts made it much faster to produce AKMs.
  • Using rivets instead of welds on the receiver, in order to speed up production.
  • Improvements to barrel, gas ports etc. to speed up manufacturing and enhance reliability
  • Weight reduction of approximately 1 kg. (2.2 pounds)
  • Retains the chrome lined barrel and chamber of the AK-47 Type-2 variant, but the barrel is pressed and pinned to the receiver, instead of the AK-47 which has a threaded barrel that is screwed into the receiver.
  • The barrel is the first in the AK family to have a slant compensator to reduce rifle climb, when shooting in automatic mode.
  • Gas relief ports are moved forward to the gas block, instead of the gas tube.
  • Bolt carrier was lightened slightly. The wooden stocks were also hollowed out as well, in order to reduce more weight.
  • Sights on an AKM are calibrated to go up to 1000 meters, whereas AK-47s are only calibrated to go up to 800 meters.
  • Changes to the metal treatment applied. The AKM is parkerized instead of blued like the AK-47.
  • Uses modified spring and trigger assembly for better safety. The AKM fires in automatic mode only when the bolt is fully locked. The new trigger assembly also reduces "trigger bounce" and has a hammer release delay device to delay the release of the hammer by a few microseconds in automatic firing mode. The hammer release delay mechanism is sometimes incorrectly called a "rate reducer" by some people, but it doesn't appreciably change the cyclic rate of fire. Instead it allows the bolt group to settle in the forwardmost position after returning into the battery.
AKM assault rifle. Click on image to enlarge. Public domain image.
Note the slanted barrel tip: that is the slant compensator, which is one of the improvements over the original AK-47 design

The AKM was used by the Soviets, most Warsaw Pact countries, several African countries and many Asian countries as well. Manufacturing licenses, as well as necessary technical data, were sold for very nominal rates (or gifted for free!) to Warsaw Pact countries, as well as other "friendly" countries like Egypt and Iraq, so that they could make their own AKMs. Because of this, it became very widespread around the world. Many variants of this design still exist in use around the world today. One popular variant of the AKM is the AKMS, which features a folding metal stock instead of the fixed wooden stock of the AKM.

AK-56: This is a Chinese made variant of the AK family. While it is officially called the "Type-56", it is often referred to as the AK-56. Predictably, the number 56 indicates that the production of the Chinese models started in 1956.  In the initial stages, the type-56 was a direct copy of the AK-47 type-1 model. However, in the 1960s, the Chinese incorporated some of the AKM improvements (e.g. stamped sheet metal receiver and slant compensator) and made some of their own modifications into their type-56 model, but did not change their version number for some reason. One visual difference between the AKM and the AK-56 is that the front sight of an AK-47 or an AKM is a partially open type, whereas the type-56 model has a fully hooded front sight. 

Chinese sailor carrying a type-56 assault rifle. Click on image to enlarge. Public domain image.

The type-56 is the most prolific version of the AK family, since it was exported by the Chinese to various communist movements, especially in third world countries of Asia, South America and Africa. Nearly one in five (i.e. 20%)  of  AK type rifles in the world today is a type-56. When US forces were in Vietnam, the type-56 was found in enemy hands far more often than AKM or AK-47s.

AK-74: This was the next rifle that was officially adopted by the Soviet military in 1974. It was based on the AKM design. However, this variant fires 5.45x39 mm. ammunition instead of 7.62x39 mm. ammunition that the older variants fire. Because of this new cartridge, the barrel, receiver, magazine, firing mechanism, gas cylinder, springs and sights are also altered to accommodate the new cartridge's dimensions and power. This rifle's magazine is made of a plastic, which makes it much more durable than the metal magazines of the AK-47 and AKM. The magazine shape is also subtly altered with two extra horizontal ribs, in order to make it impossible to insert it into an older AK model (since they don't use the same ammunition anyway). The pistol grip is made of a polymer plastic as well. Some early AK-74s have wooden hand guards and butt stock, but they use laminated wood instead of the plain wood that the earlier AK models use. Some later versions of the AK-74 use entirely polymer furniture (i.e. butt stock, pistol grip and hand guards) which is usually plum colored or black colored. The butt stock also has some cuts in it to reduce overall weight and also provide an easy way to distinguish it from an AKM.
AK-74 assault rifle. Click on image to enlarge. Public domain image.
Note the laminated wood stock with distinctive cuts on the side, laminated wood hand guards and the dark-brown plastic magazine.

There are also variants, such as the AKS-74, which feature folding metal stocks instead of wooden stocks, AKS-74U, which is a shorter carbine form of the AKS-74, AK-74M which features black plastic furniture completely (i.e. no wood parts) and has a mounting rail on the left to attach telescopic sight models etc. The firearm issued by the Russian military since the early 1990s is the AK-74M model, though earlier AK-74/AKS-74 still remain in service as well.

AK-74M assault rifle. Note the complete lack of wooden parts. Click on image to enlarge.

AK-101: This is a variant of the AK family that is meant for the export market outside Russia. That is why it is chambered to fire NATO standard 5.56x45 mm. ammunition, which is standard in many countries around the world. Naturally, many of the other parts (barrel, receiver, magazine etc.) are also modified to fit the cartridge. In short, the AK-101 is essentially an AK-74M design resized for the NATO cartridge.
AK-101 assault rifle. Click on image to enlarge. Public domain image.

Like the AK-74M, it also has a mounting rail on the side to allow attaching many optical devices that are common in Russia and Europe.

These are only a few of the models in the AK family of assault rifles. Unfortunately, many people in the media insist on calling all of them "AK-47s", in spite of the major differences between all the models. Surprisingly, true AK-47s are actually quite rare these days, especially the Type-1 variant. Most of what is referred to in the media as an "AK-47" is usually not the original AK-47 model, the weapon in question is usually a variant of AKM, a Type-56, an AK-74 etc. This became painfully apparent to the blog author when he attended a court case as a juror. The prosecutor kept referring to a firearm presented as evidence as "an AK-47 assault rifle". As the case progressed, it emerged that the firearm in question had a different firing mechanism as it was incapable of automatic fire (it could only fire in semi-automatic mode), had a laminated stock, used stamped parts and was made by an American manufacturer named Ewbank Manufacturing from Winslow, Arizona.

Tuesday, February 22, 2011

Shotguns: Why are shotguns used to break locks and why not other firearms?

In many movies, there's a scene where the upstanding hero comes running around a corner, only to be confronted by a locked gate. No problem at all for the hero, he simply pulls out his trusty pistol and shoots one through the lock and then dramatically flings the gate open. Now, let's move on to real life scenarios: when we watch US forces in action in Iraq (or police on TV), there's usually one soldier carrying a M4 or M16 rifle in his arms and a shotgun on his back. The shotgun is used to break through doors. So why do they carry such a heavy firearm, if a pistol can do the job?

One of the reasons people use shotguns is because they can use special breeching rounds with them. We just studied breeching rounds two posts earlier. One of the advantages of breeching rounds are that the slug is designed to disintegrate on impact, so there's a far smaller chance of the round bouncing off or penetrating the door and accidentally injuring the shooter, a team-mate or an innocent bystander. That's very useful in confined areas and such. There are also other reasons, which we will study about here.

First thing the reader ought to learn is never believe everything you see on TV or in Hollywood movies. The first question is whether a pistol can actually penetrate through a lock. There was an interesting article on this subject posted earlier on and we will merely post the summary here (visit the link for full details and pictures of the actual tests). The author of that article bought a bunch of laminated steel padlocks, similar to the one shown below:
These are fairly cheap locks (typically cost about $5-$10 each and cheaper if you buy six at a time) and very commonly used. Then the author of the article lined them all up and shot them from a distance of 15 feet. This was far enough so that they could avoid any ricochet problems. Note that Hollywood heroes never worry about such matters and usually shoot with the handgun held about a foot away from the lock, which is a darned stupid thing to do in real life.

In the case of handguns, the author tried using a 9 mm. pistol first (firing a ball and then a jacketed hollow point bullet), a .45 ACP (the all-american favorite!) and even a .44 magnum revolver (the Dirty Harry gun) with a jacketed hollow point bullet. In all the cases, the bullets just bounced off the locks, leaving minor dents. In the case of the .44 magnum, one pin was blown upwards off the lock due to the impact, but it still held just fine. So that's one Hollywood myth dealt with, now on to bigger weapons.

The author next fired at the locks with different rifles. First he tried with an AR-15 (the civilian version of the M16), firing 5.56 mm. XM-193 ball ammunition and also Remington .223 soft point. The rifle bullets did penetrate fully through the lock, but they all left a small hole in front and a larger hole in the back and the pins all held. In order to fully open the lock, a person would have to fire multiple times to break all the holding pins. The author also fired at a lock using a FN FAL using a .308 caliber Winchester round (i.e. civilian version of NATO standard 7.62x51 mm. cartridge) and also a .30 armor piercing round. In both cases, the rounds did blow the lower half of the lock off, but the upper part still had pins holding the lock closed. As with the AR-15, a person would need to shoot the lock multiple times to unlock it.

Finally, the author tried shooting it with a 12 gauge shotgun (this is the most popular bore size for shotguns). Since the author didn't have access to breeching rounds, he tried using a Brenneke slug instead. Result: the shotgun simply blew the padlock body to pieces with the very first shot and the padlock easily opened.

Conclusion: pistols and revolvers don't have what it takes to even penetrate a cheap, commonly used lock. Rifles will penetrate such locks, but do not reliably open the lock with a single shot. Therefore, a person needs to take multiple shots at the lock to unlock it when using a rifle, which loses the element of surprise. Only a shotgun will reliably break locks with a single shot. Add to that the fact that ricochet risks are significantly reduced when using a special breeching round with the shotgun and the reader will see the reason why real soldiers and SWAT cops carry a shotgun with them, because nothing else will do the job!

Shotguns: Chokes and Choke Boring

When a shotgun fires multiple pellets, they spread out in a cloud of pellets upon leaving the barrel. This is known as the shotgun pattern or shotgun shot spread. We've already studied how to determine the shotgun pattern earlier and the reader is advised to refresh their memory from the earlier article.

Now the key is that the largest number of pellets must penetrate in a 30 inch diameter circle, such that if a bird silhouette was to be placed on the circle, that the silhouette cannot be placed anywhere where at least 3 pellets are not going through it.

In order to increase the number of pellets within the 30 inch circle, a choke is often employed. Chokes may be built into the barrel, as part of the manufacturing process, or the end of the barrel may be threaded and the user can screw on a removable choke to the end of the muzzle as needed. This way, the user may be able to use different chokes depending on the number and diameter of the pellets used.

Since removable chokes are more modern, we will now study the history of choked barrels (i.e.) barrels manufactured with a built in choke.

The basic principles of choke-boring seem to have been invented by Spaniards, as we find the first mention of improving shooting patterns by various boring methods in Spanish books. M. de Marolles in his book, La Chasse au Fusil, states that some gunmakers in his time maintained that, in order to throw shot more closely, the barrel diameter should be narrower in the middle than on the breech or the muzzle end; while others insisted that the barrel must gradually contract from breech to muzzle. He goes on to describe methods to achieve these results, as were in vogue during his time. J.W. Long, an American author, in his book, American Wild Fowl Shooting, claims that choke-boring was an American invention and attributes the discovery to one Jeremiah Smith of Smithfield, Rhode Island, who was making choke-bored barrels, as early as 1827. The first known patent was granted to an American gunsmith, one Mr. Roper, on April 10th 1866, who preceded another claimant, an English gunmaker, Mr. Pape, by just six weeks.

While these early inventions were by American gunsmiths, they had not fully understood choke boring and therefore, a lot of their guns would lead, shoot irregular patterns and not shoot straight. It was left to an English manufacturer, W.W. Greener, to invent a method of choke boring that became the most widely used method in the later part of the 19th century. It was because of the popularity of the Greener method of boring that some authorities falsely give W.W. Greener the credit for inventing choke boring, though he himself never claimed to invent it.

W.W. Greener was a well-known gunmaker in Birmingham in the 19th century (the firm is still around today). His first intimation of a choke formation was from a customer's letter in early 1874. This customer had ordered a custom gun and in his special instructions to Greener, he described a choked barrel, though he did not specify its size or shape, or how it was to be obtained. However, W.W. Greener was intrigued enough to conduct many experiments to determine how to make the best profile and size of the choke for any given bore diameter. He also invented new tooling to make this boring possible. After many months of experimenting, he figured out how to make appropriate choke profiles for any bore of shotgun.

The Greener choke consists of leaving the barrel mostly cylindrical, but creating a constriction in the barrel towards the muzzle end of the barrel, as can be seen in the figure above. Before this method was invented, most people would either make the breech end of the barrel of a slightly larger diameter for up to 10 inches of barrel length from the breech, or they would bore the middle of the barrel to a smaller diameter and make the breech and muzzle of a larger diameter, or they would simply leave the barrel as a true cylinder (no choke).

On December 5th 1874, Mr. J.H. Walsh, the Editor of Field magazine,  mentioned the Greener choke in an article, that read:
"We have not ourselves tested these guns, but Mr. W.W. Greener is now prepared to execute orders for 12-bores warranted to average 210 pellets of No. 6 shot in a 30-in. circle, with three drachms of powder, the weight of the gun being 7.25 lb. With larger bores and heavier charges, he states that an average pattern of 240 will be gained. As we have always found Mr. W.W, Greener's statements of what his guns would do borne out by our experience, we are fully prepared to accept those now made".

The article created a sensation because the very best 12-bore shotgun in the London public gun trial of 1866 could only generate an average pattern of 127. The very next issue of Field magazine contained an ad from W.W. Greener guaranteeing a pattern of 210 on his 12-bore guns. There was also a letter to the Editor in the next issue, from a reader of the magazine, confirming that his latest purchase from W.W. Greener did indeed meet this claim and more. Naturally, such statements created a huge controversy among gun manufacturers and readers, and the Editor of Field magazine was compelled to send a Special Commissioner to witness and verify the shooting of  Greener guns. The Special Commissioner not only verified the claims, he actually got an average pattern close to 220 during his testing! After that, several other manufacturers claimed to be in possession of the same method of boring as W.W. Greener and therefore, the proprietors of Field magazine decided to conduct a public trial, the London Gun Trial of 1875, to verify various manufacturer claims. Greener-made choke bores won overwhelmingly in this trial, as well as the London trials of 1877 and 1879 and the Chicago trials of 1879 and led to the fame of his company spreading.

The Greener method of choke-boring was later adopted by other manufacturers and became the dominant form of choke boring. Modern chokes today are usually screwed on to the muzzle end of the barrel and slightly change the diameter of the muzzle in much the same way.

Sunday, February 20, 2011

Shotguns: Ammunition

Shotguns are designed to fire a wide variety of ammunition, generally more than other firearm types. We will look at the various types of ammunition in this post.

Before we start, the reader is advised to revisit an earlier article on bore/gauge of a shotgun, which will come in useful to understand some concepts discussed in this article. The reader may also find it useful to peruse the article on shotgun pattern testing.

The first, and most common type, is the shotshell. This is a cartridge that contains a number of pellets, usually made of lead, steel alloy, bismuth alloy or titanium composite. The most common type of shotshell is birdshot, which is commonly used to hunt birds. It consists of a cartridge containing dozens to hundreds of small pellets or ball-bearnings.

Public domain image

The shotgun shell is cylindrically shaped. In earlier days, the outer case was made of brass or thick paper. Modern shotgun shells are usually made of plastic with a thin hollow brass base cover, such as the illustration above. From left to right, we have the brass base of the cartridge, the propellant material (the gray part) which sits inside the brass base and extends out of it, a lot of wadding (the olive, pink and brown bands), the shot pellets and finally, another wad (the brown band on the right) that holds the shot pellets in the cartridge. The purpose of the olive, pink and brown wad is two-fold. First, it provides a gas seal between the pellets and the propellant. If it is not there, the propellant gas will simply flow through the gaps between the pellets instead of propelling the pellets. The second reason is that the wadding acts as a shock absorber or a cushion. When the shell is fired, the wadding gets crushed first and absorbs some of the shock. Without it, many pellets could get deformed by the propulsive force and thereby fly in the air erratically. The cushioning provided by the wadding prevents this.

The pellets in a shotgun shell are of uniform size. In earlier days, the pellets were mostly made of lead, using a process we described previously, because lead is cheap, easily formed and widely available. However, lead is a poisonous substance and can cause lead poisoning (e.g.) pellets that fall into ponds when hunters are hunting water birds. Water fowl could accidentally ingest some of these pellets and end up poisoned. Then, these could be eaten by birds of prey or animals and in turn, they get poisoned as well. People drinking the water could get affected too. These days, the environmental effects of lead are being taken more seriously and therefore, lead pellets are banned in several areas. Hence, modern pellets are now made of steel, bismuth or titanium composites.

Birdshot, like the name suggests, is used to hunt birds. Different gauges are used depending on the species of birds being hunted.

The next variation of shotgun shells use buckshot. These are similar to birdshot, except that the pellets are larger in diameter. Buckshot is designed to take down larger game animals, such as deer (which is why it got the name "buck" shot).

The next common variant is the solid slug. This is a single, solid, heavy bullet used to hunt large game. Many slugs already have rifling cut into them. The first design of a solid slug was from a German designer called Wilhelm Brenneke in 1898. His design has remained largely unchanged until now.

A Brenneke slug. Public domain image

The above image is of a Brenneke type slug. Notice the grooves cut into the sides of the slug. As before, there's a large amount of wadding (the white and brown parts) between the propellant and the slug. This kind is very popular in Europe and sometimes referred to as "European type" slug.

Another design is the Foster slug, designed by an American named Karl Foster in 1931. In this type of slug, there is a deep hollow inside, so that the center of mass is closer to the tip of the slug. This is designed for smoothbore barrels and because of the position of the center of mass, it doesn't tumble in the air because the drag causes the back of the slug to stay behind the front (much like a shuttlecock's feathers). This type is popular in the US and is sometimes referred to as the "American slug". It is also possible to fire this type of slug through a rifled barrel, but it causes lead buildup in the rifling grooves to happen at a faster rate.

Yet another type is the sabot slug. The word "sabot" comes from French, where it was used to describe a type of shoe worn by many workers during the industrial age. Incidentally, there was a period where the French workers went on strike, protesting their work conditions, and threw their sabot shoes into the industrial machines, hoping to jam them up. This is the origin of the word "sabotage"! In a sabot slug, the slug is usually an aerodynamic shape that is smaller than the barrel, surrounded by an outer shoe (the sabot) that provides a tight gas seal. The sabot gets deformed by the propellant pressures, while the slug inside is largely undeformed and intact. In case of rifled barrels, the sabot also has the rifling and therefore provides spin to the bullet. Once the bullet clears the barrel, the sabot separates from the bullet and falls down and the undeformed bullet continues on its way. This provides for better accuracy and faster velocity of the bullet. On the flip side, sabot slugs are more expensive and more time-consuming to manufacture.

The next type of shotgun ammunition is the bean bag round, also known by its trademark, flexible baton round. It consists of a small fabric container filled with birdshot. It is designed to be "less lethal" than the rounds we've studied so far. This type of round is designed to stun a person rather than kill them. Of course, fired at close range, it can be lethal as well. In longer ranges, it could be lethal if it strikes a vulnerable part of a person's anatomy, such as the throat or solar plexus. This type is typically used by police to incapacitate and capture a suspect. Other variations use rubber shot instead of bean bags for the same effect.

Another older form of the bean bag round was the rock salt shell. As the name suggests, shells were filled with rock salt crystals. Since salt crystals are brittle, these shells were not as lethal at longer ranges, but still caused a stinging bruise, enough to dissuade a person from attacking. These were used by police and rural farmers in earlier days.

Another type of shotgun shell is used for riot control. This is the gas shell and it normally contains pepper gas or tear gas.

Breaching rounds are often seen in use with police and military units. This is a special round designed to destroy door locks and door hinges, without endangering nearby bystanders. These rounds are also called Disintegrator or Hatton rounds. The slug is made of a dense metal powder, which is held together by a binder material such as wax. When fired at a door lock from close ranges, the slug destroys the lock and quickly disintegrates into a metal powder, instead of ricocheting somewhere or penetrating through the door. This is what makes is suitable to be used in tight confined spaces.

There are also other ammunition types, such as those that provide a lot of flash, or a whistling noise. These are used to scare or disorient animals, but are not lethal.

As you can see, there are many types of ammunition for shotguns, all for different uses.

Wednesday, February 16, 2011

Shotguns: Hammerless Shotguns

In this post, we will look at a class of shotguns called "hammerless" shotguns. To understand hammerless shotguns, first let us look at a shotgun that has hammers.

The above picture shows a double-barreled shotgun. The hammers are the two roughly S shaped pieces you see in the image. To cock the shotgun, the user pulls back the hammers using the long spurs at the end of the hammer, until they lock when pulled back. Then the user applies a percussion cap to each of the brass nipples of the shotgun. When the user pulls a trigger, the hammer is released. Due to a spring attached to the hammer, the hammer strikes the percussion cap with considerable force, which detonates it and then discharges the firearm. This sort of design has existed since the earliest shotguns.

Now that we know what a shotgun with a hammer looks like, we will now look at a hammerless shotgun.

In the above picture, we have a hammerless shotgun. Note the absence of the two hammers near the open end of the barrels (the breech). The lever that you see behind the barrels is merely a lever that holds the barrels down when the shotgun breech is closed. So does this mean that this weapon has no hammers? Actually, this weapon does have hammers, but they are hidden inside the weapon. The word "hammerless" is a misnomer and it should really have been called "internal hammers".

Unlike the first shotgun we saw, which had external hammers (or exposed hammers), a hammerless shotgun actually has internal hammers, which are hidden inside the action, as shown in the figure below

In the above diagram, A is the hammer. In this above design, when the barrels are tilted downwards, the projection C rotates the hammer A backwards, against the pressure of spring B. The hammer A rotates until the lever D catches it and holds it in place, as shown in the picture above. When the user pulls the trigger, the lever D pivots and releases the hammer A, which then allows spring B to expand and makes the hammer strike the base of the cartridge, thereby discharging the shotgun.

One of the disadvantages of an external hammer is that the hammer spurs can get caught on items, such as clothing, small branches etc. and thereby cause accidents or failure to fire. With internal hammers, such an event is not possible.

The first hammerless shotguns came some obscure French and Belgian manufacturers in the early 1800s. In the 1830s, there was a hammerless shotgun developed by a Prussian gunmaker named Dreyse. We studied this gun when studying the side-motion action.
In here, turning the lever at the bottom, not only rotated the barrels around an eccentric path, they also cocked the two internal hammers.

The next advances were by an English gunmaker named Needham in 1856 and another English maker named Daw in 1862:

Needham Hammerless Gun from 1856. Click image to enlarge. Public domain image.

Shotgun made by Daw in 1862. Click image to enlarge. Public domain image.

In these versions, a long lever is placed in front of the triggers, as can be seen in the figures above. This lever can be pushed out to cock the internal hammers and eject the old cartridges and then folded back into place. Many of the early hammerless shotguns used a plan like this.

Of course, with such an approach, the user has to open the breech, then push the lever to eject the old cartridges and cock the gun, pull the lever back into place, then put in new cartridges and then shut the breech and lock the barrels into place, before firing the weapon. In order to make the whole process more efficient, some manufacturers attempted to reduce some of these steps.

During the period of 1875 to 1878, several London and Birmingham gunmakers attempted to make self-cocking guns, which would get cocked automatically upon opening the breech. The first successful hammerless action of this type was the Anson and Deeley action, which was invented in 1875 by two gunsmiths named Anson and Deeley, who were then working for the British manufacturer Westley-Richards and later formed their own company. They were followed by other British manufacturers such as Green, Scott, Parson, Rigby, Greener, Purdey, Walker etc. One such action working on these principles was already described above and we reproduce the illustration again so that the reader doesn't have to scroll up.
The basic Anson and Deeley design quickly became the dominant form of hammerless action and has remained almost unchanged to the present day. Since the original design had only 4 moving parts, it was cheaper and more reliable than other hammerless actions of its day, which contributed to its popularity.

In America, the first hammerless design was by Daniel LeFever in 1878. At that time, he was working with a partner named John Nichols in Nichols & LeFever Co. Like the early European designs, his shotguns had a separate lever to manually cock the shotgun. In 1880, LeFever formed his own separate company, the Lefever Arms Company. In 1883, he improved his hammerless design so that the separate lever was no longer needed. Unlike the European designs which would cock the internal hammers upon opening the breech, his 1883 design would cock the internal hammers upon closing the breech. He also later patented an automatic ejector which would eject the old cartridges when the breech was opened. In 1912, the Lefever Arms Company branched out into manufacturing gear boxes (selective and planetary transmissions) and jackshafts for the newly emerging automobile industry. Lefever Arms Company was an independent manufacturer until 1916, when the gear manufacturing side was merged with the Durston Gear Company and the firearms manufacturing side was bought out by the Ithaca Gun Company. The Ithaca Gun Company made some cheaper weapons using the LeFever name until 1941, but these weren't very good quality and were only exploiting the good reputation of the LeFever brand name. Original Lefever Arms Company guns from before they were bought out, still command high prices today and are regarded as some of the finest shotguns ever made in America.

"Hammerless" actions exist for other types of firearms as well. For instance, one can also find revolvers and pistols that have internal hammers.

Monday, February 14, 2011

Shotguns: Actions and Designs

The early history of true shotguns begins in the 1800s, when people began to use them to hunt birds. During that time, the flintlock firing mechanism was the ignition system of choice and hence, it should be no surprise to know that early shotguns used them. The problem with such mechanisms is that there is a noticeable delay between pulling the trigger and the weapon actually discharging. The Rev. Alexander Forsythe, a Scottish clergyman and an avid hunter, noticed that the local birds would see the flame in the pan and immediately change direction and thereby escape. Hence, he set about inventing the percussion lock, which was the next big development in firearms technology and was also used by other firearms besides shotguns. The percussion lock was eventually replaced by modern cartridges, which we use to this day.

Shotguns come in both single barrel and double-barrel types. Double-barreled shotguns have two triggers, one to discharge each barrel. Of the double barreled shotguns, there are two types: "side by side" type and "over and under" type. What this means is how the two barrels are positioned. In "side by side" types, the barrels are placed beside one another, whereas "over and under" types have one barrel positioned on top of another.
"Side by Side" type shotgun

"Over and Under" type shotgun

Double barrel shotgun barrels are never attached parallel to each other, but instead set so that their shot will converge at some point (usually at 40 yards distance). In some shotguns, one of the two barrels may be made different from the other. For instance, one may have rifling and the other is smoothbore, or one barrel may be choked for closer shooting. In other cases, both barrels may be made as identical as possible.

Of all the actions, the break-open action, such as the two images above, is the most common type and has been around for a long time. This is a breech-loading mechanism. It was realized in 1875 that the movement of opening the action could also be used to cock the weapon at the same time. The first such cocking mechanism was pioneered by Anson and Deerley for their hammerless shotgun and it is still used almost unchanged to this day. Break-open actions are the most common type used for shotguns.

Another action that was invented in the mid 1800s and rare today, is the side-motion action. In this type of action, the barrels are mounted on the edge of a metal disc. A lever in the bottom of the stock rotates this disc, which causes the barrels to move in an eccentric motion, where they can be reloaded.

Another action that was invented in the 1800s, but is rare now, is the sliding barrel action shotgun. There are only a few manufacturers around that make this type currently and it was never as popular in the 1800s either.

Sliding Barrel Action Shotgun

Lever action shotguns were popular in the 1880s. The Winchester model M1887 was designed by John Browning and became a best-seller for the company. This was the first truly successful model of a repeating shotgun. This action allowed for users to load multiple cartridges into the weapon, not just one or two cartridges. Their popularity waned after the design that we're about to study in the next paragraph was introduced, and we don't see too many lever action shotguns these days.


The action that replaced the lever action design is the pump action shotgun design. The first popular ones of this type were the Winchester M1893 and M1897 models, which were designed by John Browning! It must be noted that when Winchester originally asked Browning to design a repeating shotgun in the 1880s, he had argued that a pump-action mechanism shotgun would be the most appropriate design, but Winchester was a lever-action manufacturing company, so they persuaded him to design a lever-action shotgun, which was the M1887 model described above. However, they did later manufacture his pump-action design as the Winchester model M1893, which was later improved to the model M1897. It must be noted that the M1897 shotgun gained so much popularity that it was used by US soldiers in World War I, where it was found very useful for trench fighting. Its quick shooting speed and massive stopping power made it a very effective weapon for US soldiers to have. In fact, the German troops feared this weapon greatly and the German High Command even attempted to have it outlawed in combat, by citing Geneva convention laws (this coming from the same people that allowed the use of poison gas!). The pump-action shotgun design is still popular to this day.

Pump Action shotgun

There are also semi-automatic shotguns, where some of the force generated by the firing cartridge is used to eject the old cartridge, cock the action and load a new cartridge. Semi-automatic shotguns use a variety of mechanisms: long recoil action, inertia operated action or gas-operated action. The first successful semi-automatic shotgun was the Auto-5 (or A-5) action first designed in 1898 by (surprise, surprise) John Browning! The Auto-5 model remained in production until 1998!

Semi-automatic Remington Model 11 shotgun using long-recoil action

Bolt-action shotguns also exist in the wild, though they are not common. One particular model was manufactured in .410 caliber by the Ishapore arsenal of India, based on the Lee-Enfield SMLE Mark III model.
Ishapore .410 caliber bolt action shotgun. Click on image to enlarge.

In the next post, we will look into more about shotguns.

Thursday, February 3, 2011

Shotguns: Basics

In our last post, we looked at a type of firearm called the blunderbuss. These weapons faded out of popularity around the end of the 18th century. In the next few posts, we will study a descendant of the blunderbuss, the shotgun.

A shotgun is typically a shoulder-fired weapon of short range. The barrel is generally smooth, though some modern shotguns may be rifled as well. Shotguns typically fire a cartridge that contains a number of small pellets (shot) or a single solid projectile (slug). The ability to fire multiple shot pellets simultaneously is what distinguishes a shotgun from other firearms. The shot pellets spread out over an area upon leaving the barrel. The force of the burning propellant is divided among all these shot pellets and hence the energy transferred to any individual shot is fairly low.

Winchester model 1897, pump-action shotgun. Click image to enlarge. Public domain image from

Shotguns were historically shorter than rifles and hence easier to manipulate in close quarters. However, they had  much more power than pistols, since they were designed to be supported from the shoulder. For this reason, they were traditionally used by cavalry and coachmen as a close range defensive weapon. In previous centuries, banks would send money in stagecoaches and the person sitting next to the driver would carry a large shotgun with him. This is the origin of an American slang term that still exists to the present day: "riding shotgun". For non-US readers of this blog, this slang term means the person who's sitting on the front passenger seat next to the driver in a modern automobile. A common tradition observed in the US: when a group of friends are planning to travel together somewhere by automobile, the first person who yells "shotgun" upon seeing the vehicle that they are travelling in, gets the privilege to "ride shotgun" (i.e.) sit in the front passenger seat. It is considered against the rules to yell "shotgun" before the vehicle is visible, to prevent people from reserving the front passenger seat well in advance.

Shotguns were also traditionally used to shoot birds and small fast-moving game animals (such as rabbits, hares etc.) Because these offer small targets and move very rapidly, it is difficult to aim at them exactly. Since a shotgun fires multiple shot pellets which spread out over an area, it is not necessary to aim as precisely when using a shotgun. We already discussed how to measure how the shotgun spreads its shot out in an earlier post.

Shotguns are also used by military and police as short-range weapons, especially useful in trench warfare, urban combat and riot control situations. The shotgun has been in and out of military use throughout history, but the US military rediscovered its usefulness around World War I and it has remained in use since then. The picture below shows some US Marines in action in November 2005. Note that the Marine in front is carrying a shotgun.

Public domain image. Click on image to enlarge.

Shotguns are also very popular for home-defense use because of the spread-out nature of shot (i.e.) it is not necessary to aim accurately, which comes in useful if there is a break-in at night. A shotgun fired in the general direction of an intruder results in multiple wounds to the intruder, which is likely to incapacitate him or her. However, since each individual pellet has lower power than a rifle, it is less likely to penetrate the walls and injure a neighbor or a bystander. A shotgun also looks more intimidating than a pistol or revolver. Additionally, the distinctive click sound of a shotgun being cocked is often enough to deter many would-be burglars.

Shotguns typically come in a number of calibers, from a small .22 caliber shotgun to massive punt guns. They take a variety of ammunition types: shot pellets, solid slugs, bean bags and rubber bullets (for riot control and non-lethal use), tear gas or pepper spray (for riot control), breaching rounds (for destroying door locks and hinges) etc. We will study all these types of ammunition as we study shotguns in future posts.