The Boys Anti-tank Rifle

In our last post, we studied the world's first anti-tank rifle, the Mauser T-Gewehr M1918, which was invented by the Germans. Today, we will study the history of another anti-tank rifle, the British Boys Anti-tank Rifle.

In the last post, we studied that the Mauser T-Gewehr was invented by the Germans because they didn't have any tanks of their own during World War I and had to come up with some solution to counter British and French tanks. Although tank armor had become thick enough to resist the Mauser by the end of World War I, the idea of an anti-tank rifle did not go away.

In 1934, the British decided to design a weapon that could penetrate light armor. The project was originally called Stanchion and was given to the Royal Small Arms Factory of Enfield, Middlesex, England to design. The chief designer of this project was a Captain H.C. Boys.

Captain Boys intended the rifle to be a bolt-action large bore rifle, capable of penetrating light armor, but light enough to be carried by a single person. He looked at the existing rifle cartridges of the day. The 30-06 and the .303 cartridges were found to be too weak (even the armor-piercing variants). The US made Browning .50 BMG cartridge was found to have some potential, because it could penetrate 3/4" armor at 100 yards, but they wanted something a bit more powerful than the .50 caliber cartridge. Therefore, they started with a Browning .50 caliber cartridge case, widened the case's neck to accept a .55 caliber steel-core bullet and added a belt around the cartridge base for proper headspacing (the idea of adding a belt on the base of a magnum cartridge was a British invention by Holland & Holland in 1910 for their larger hunting rifles firing the powerful .375 H&H magnum cartridges). This new cartridge weighed 946 grains (64 gm.) and had a velocity of 2495 feet/sec, delivering 17726 ft-lbf (24033 joules) of energy. By comparison, the .30-06 cartridge (all variants) delivers somewhere between 2800 to 3000 ft-lbf of energy. The job of manufacturing the new .55 caliber cartridge was given to Kynoch Ltd., a well known manufacturer of cartridges in England.

With the cartridge designed, the next goal was to design a rifle around this cartridge. It was simply a bolt-action design with a 5-round magazine, weighed about 35 lbs. (16 kg.) and was about 5 feet 2 inches (1.575 meters) long. The magazine was top-mounted and therefore, the sights were offset to the left to accommodate this. Tragically, the designer of this rifle, Captain Boys, died a few weeks before the rifle went into production in November 1937. Hence, the rifle was renamed as the Boys Anti-tank Rifle in his honor.

The Boys Anti-tank Rifle Mark I. Click on image to enlarge. Public Domain Image.

The rifle was manufactured in three variants. The Mark I variant (as shown in the image above) was the original design manufactured by the Royal Small Arms Factory in Enfield. Notice the round muzzle brake and the T-shaped bipod The Mark I* was given to the Canadian company, John Inglis & Co.  to manufacture and this variant had a V-shaped bipod and flat muzzle brake. The Mark II Airborne variant was designed to be carried by paratroopers and had a shorter muzzle.

When the Boys rifle was delivered, it was not effective against German panzers since the very beginning of World War II. While the bullet fired by this rifle could penetrate through mild steel plate of 23.2 mm. thickness (almost 1 inch thick) at about 90 meters (100 yards) range, the frontal armor of the German tanks was thicker and harder than this and therefore the rifle didn't fare very well against them. However, they proved to be more effective against armored cars and Soviet and Japanese light tanks. The Finns used them against Soviet tanks in 1940. The original steel-cored bullet was later replaced by a tungsten-core bullet (the .55 Mark II cartridge) in an attempt to improve its effectiveness. Despite the cushioned butt pad on the stock, the recoil from this weapon was terrific and often ended up bruising the operator's shoulder, which made soldiers very reluctant to fire it unless it was mounted to a support. This weapon did find some success with the British commandos of World War II (the Desert Rats), who mounted it to the top of their trucks and Bren carriers, when they went on raids in the desert.

Since the rifle had such a heavy recoil, an adapter kit was designed to be used by this rifle for training purposes.

What the adapter kit did was allow the user to mount a smaller .22 caliber rifle to the side of the Boys rifle and fire that via the trigger of the Boys rifle. This allowed for users to learn basic sighting techniques, without having them to bear the force of firing the Boys rifle during training sessions.

The Walt Disney Company was also commissioned to produce a training video for this gun during World War II:

Yes, that is a Disney cartoon animation at the beginning of the first video.

While the Boys rifle was largely ineffective in its original role of stopping German tanks, it was more effective against lighter skinned vehicles, early Soviet and Japanese tanks and armored vehicles. US Marines used it against Japanese bunkers as well. By the end of World War II, this rifle was seen as obsolete and was replaced by bazooka type anti-tank weapons. However, they were still used in the Korean war and in the Philippines until 1960 or so. One was even used in the 1960s by the IRA to disable a British Navy Patrol Boat HMS Brave Borderer by shooting out one of its turbine engines through the hull of the boat.

The Mauser Anti-tank Rifle

In today's post, we will study a special firearm that was developed during World War I. It was the world's first anti-tank rifle and it was developed by Mauser. This particular rifle was called the Mauser Tankgewehr M1918 (or Mauser T-Gewehr for short). The word Tankgewehr is German and means "tank rifle".

During World War I, the invention of the tank revolutionized modern warfare and gave British and French troops a significant advantage on the battlefield. When it was first introduced, the British Mark I tank was almost invulnerable to the ordinary rifles possessed by the German troops in the trenches. The Germans tried several tactics to neutralize British tanks.

The first attempt that the Germans made was to develop a "reversed bullet". This was simply a cartridge with the same case and bullet as the normal cartridge, but the bullet was turned backwards and extra propellant was added to the cartridge case. Since it used the same bullet and cartridge case, it could be fired by the infantry rifles that the Germans were already using. When such a cartridge was fired, the extra propellant would push the bullet at a faster speed than a normal cartridge and because the bullet was placed in backwards, the blunt end of the bullet would hit the tank first. If fired at closer ranges, the bullet would not shatter on the armor plating of the tank, but would instead penetrate it. In many cases, it would not always penetrate, but would significantly dent the tank's armor and cause shrapnel to fly in the interior compartment and kill or wound the people inside the tank. However, this cartridge was only effective at close range and because it carried extra propellant, it could damage older rifles or cause them to burst, thereby endangering its user and people around him.

The next attempt was to develop a special "K-bullet". This bullet was a 7.92x57 mm. bullet similar to what the Germans were already using at that time, but it was made with a hard tool-steel core. This meant that it could penetrate armor better than other bullet types. In fact, it had a 33% chance of penetrating 12-13 mm. thick armor plate at a range of 100 meters (330 feet). Like the reversed bullet, this could also be fired out a standard German infantry rifle. However, the K-bullet was more expensive to produce and hence was only issued to specialized snipers. Also, like the reversed bullet, the K-bullet cartridges also often damaged rifles, especially older ones and therefore wasn't very popular. In addition to this, when the British introduced the Mark IV tank during the battle of Messines Ridge, the K-bullet couldn't penetrate its thicker armor effectively.

Therefore, the Mauser factory came up with an entirely new rifle, specifically designed to fight against armored vehicles.

The Mauser T-Gewehr M1918. Click on the image to enlarge.

Image licensed under the Creative Commons Attribute-Share Alike 2.0 France license by user Rama at wikipedia.org

The Mauser Tankgewehr M1918 was developed in 1918, as the name suggests. It was a bolt-action design, using the same tried and tested Mauser M-98 action that was used in their bolt action rifles from 1898 onwards. The rifle was single-shot and rounds were loaded manually into the chamber. Sights were calibrated between 100 and 500 meters. The rifle and bipod together weighed about 18.5 kg. (or about 40 lbs.), so a two man crew was required to operate this -- a gunner and an ammunition carrier, who was also trained to fire the rifle, in case the gunner was injured.

The cartridge for this rifle was a 13.2x92 mm. cartridge, with a special hardened steel core bullet. The rifle did not have a muzzle brake and there was no recoil pad in the stock either. This meant that the rifle had a very heavy recoil and often injured the shoulder of the person firing it. Nevertheless, approximately 15,800 of these rifles were produced. Unfortunately for the Germans, this rifle came rather late in the war. Mass production of this rifle began in May 1918 and by November 1918, the end of World War I was declared.

This was the world's first anti-tank rifle and pioneered the use of other large caliber firearms in the future. We will study some of those in the following posts.

The Richardson R5 Philippine Guerilla Gun

In our last post, we studied about a survival rifle that was designed for backpackers and hikers. Today, we will study an unusual firearm that was originally constructed in the jungles of the Philippines. We're talking about the Richardson R5 Philippine Guerilla Gun.

First, we will talk about an extraordinary gentleman named Iliff David Richardson, who was responsible for manufacturing and marketing this gun in the United States. Mr. Richardson originally enlisted in the US Navy as an ensign at the start of World War II and was stationed in the Philippines. His PT boat was one of the boats that was involved in the operation to evacuate General Douglas MacArthur out of the Philippines to Australia. He continued to serve on his PT boat until it was sunk by Japanese Navy float planes a month later. After this, he enlisted in the US Army and was involved in the fighting around Cebu city in the Philippines. He and a dozen other Americans attempted to escape in a native outrigger canoe to Australia, but the canoe sank in a storm and Mr. Richardson managed to reach the island of Mindanao after a long swim. There, he came into contact with Philippine resistance fighters and joined forces with them. Since he was a trained ham radio operator before the war, he was put in charge of setting up communications between the various resistance groups and allied forces in Australia and coordinating their efforts. He did this for about 3 years, until the US forces reoccupied the Philippines in late 1944. For his work in the war, General Douglas MacArthur made him a US Army Intelligence major and he had the unusual distinction of holding commissions in both the US Army and the US Navy simultaneously. His heroics came to the attention of the public towards the end of the war and Hollywood even made a movie, "American Guerilla in the Philippines", partly based on his adventures.

Iliff David Richardson in late 1944. Click on image to enlarge.

During his time with the Philippine guerillas, he noticed that they made simple firearms called Paliuntod and Paltik. These were one-shot weapons that were designed to be used to overcome an enemy soldier in a surprise attack and then take his weapon. In this, they were similar in purpose to the FP-45 Liberator pistol that we studied a couple of years ago.

A Paliuntod shotgun. Click on image to enlarge.

These weapons were originally invented and used by Filipino guerillas during the American occupation of the Philippines and continued to be used during World War II and can still be found in use currently. The shotgun above consists of a crude barrel made from a soft metal tube sliding over another tube. The user would push it forward (as shown in the image above) and load a cartridge into the back of it. The firing mechanism was extremely primitive as well. It consisted of a fixed firing pin, which was a nail that was fixed to the handle. To fire it, the user would simply slide the barrel back hard enough so that it slammed against the nail, which would detonate the cartridge and fire it. There was no rifling in the barrel and the weapon was only effective at short ranges and was mainly used to disable an enemy and take his firearm. Several guerillas who had fought with Richardson used these weapons against the Japanese.

After the war, Mr. Richardson came back to the US and found that he was regarded as a celebrity. He started a company called Richardson Industries in 1946 to manufacture the type of weapons that they used against the Japanese. He called his creation the Model R5 Philippine Guerilla gun. Compared to the guns used by the guerillas, the model R5 was made of comparatively better materials.

A basic model R5 Richardson Guerilla gun

It consists of a simple wooden stock with a guide tube attached to it. At the back of the guide tube is a fixed firing pin. The barrel is a smaller diameter steel tube with no rifling, that can slide within the guide tube. The barrel is large enough to hold a 12-gauge shotgun shell. To load this firearm, the user slides the barrel out and inserts a shell into it. Then the user slides the barrel carefully back into the guide tube. To fire the gun, the user grabs the stock with one hand and the barrel with the other hand and strongly slides the barrel backwards to slam the cartridge against the fixed firing pin, which fires the gun. Note that the only thing that holds the breech closed is the strength of the user's two arms. There are no sights on this firearm and it is only meant to be used at close ranges. The little metal piece you see where the trigger should be is actually a safety device. It is simply a metal bolt that prevents the barrel from moving backwards far enough to strike the firing pin. A more advanced model of this rifle has a lever that looks like a trigger, but the mechanism actually controls a cam that prevents the barrel from sliding forwards or backwards until the trigger is pulled. The advanced model also has a grip attached to the barrel to make slamming the barrel back easier. The basic model has only 5 parts and the advanced model has 17 parts! The stock has the name of the manufacturer ("Richardson Industries Inc., East Haven, Conn., USA"), carved on one side and the words "Philippine Guerilla Gun, Patent Pending" carved on the other side (this message is visible in the image above). The stock is made of cheap wood and there is no butt plate.

Barry from Moss Pawn and Gun demonstrating the advanced Richardson model. Courtesy Iraqveteran8888's channel.

Despite the fame of the creator, this gun never sold very well because it was very impractical to use and production stopped about one year later. The price of this gun, when it was first sold, was only $7, but it now sells as a collector's item for as much as $350-$400 today.

The AR-7 Survival Rifle

A few months ago, we had discussed the amazing Soviet Space Pistol (TP-82), which was designed to be used as a survival weapon in remote areas. In today's post, we will look at a weapon that was designed in the US for a similar purpose. We are talking about the Armalite AR-7, known these days as the Henry Survival Rifle.

The Armalite AR-7 was designed in 1958 by Eugene Stoner, the same gentleman who designed the AR-15 and M-16 rifles. The AR-7 was based on the older AR-5 which was developed as a survival weapon designed to be used by aircraft personnel and carried in emergency kits stored aboard aircraft. The AR-5 was adopted by the US air force, but they only ordered very small numbers, therefore Armalite used some of the tooling that was originally developed for the AR-5 to create the AR-7 for the civilian market. The rifle was released to the civilian market in 1959. It was meant to be used by bush pilots, backpackers, hikers and amateur explorers.

As a bare-bones survival rifle, one of the primary requirements was for the design to be light and portable. Therefore, the AR-7 was made from plastics and aluminium alloys to reduce weight. The rifle was also designed to be compact so that it could fit inside a backpack. Therefore it was designed so that the parts could be disassembled and stored inside the plastic stock!

An AR-7 stored in a disassembled state. Click on image to enlarge.

When the rifle is stowed within its stock, the whole package can float on water! This rifle is designed to use the popular .22 LR cartridge, which is the most commonly available rifle cartridge in the world. It has a semi-automatic action and can hold 8 cartridges within its magazine. The entire rifle weighs 3.5 pounds (about 1.58 kg.) The rifle is also designed to be disassembled without any tools. The stock attaches to the receiver with a long screw bolt and the barrel screws on to the receiver, both of which can be manipulated using just a person's hands.The entire rifle can be assembled or disassembled in about 30 seconds. 

An assembled AR-7 rifle. Click on image to enlarge.

The rifle was designed for an 8 round magazine originally, but there are now other magazines for it that can hold 10, 15, 25 or 50 rounds as well. Accuracy is pretty decent and it can be used to hunt small game animals.

Armalite sold the rights to the design to Charter Arms in 1973. According to some people, Charter Arms didn't manufacture their rifles with the same quality as Armalite and the rifle started to gain a bad reputation during this period. Charter Arms later sold the design to the Henry Repeating Arms company in 1980. The Henry Repeating Arms company slightly revised the design and produced a much better quality version than Charter Arms and after that, the bad reputation it had collected in the previous few years went away.

The version that is now made by Henry Arms has two 8-round magazines stored in the stock (latest versions have 3 magazines). The plastic stock is now made of ABS plastic which is tougher than the original plastic stock and does not crack easily. It is also much more water-resistant than the older stock. The receiver and barrel are coated with teflon for better corrosion resistance

An AR-7 was even featured in the James Bond movie To Russia With Love starring Sean Connery.

What is Simunition?

In modern training situations, there is a need to allow police officers and soldiers to practice with the same weapons that they normally use as part of their job. This is where simuntion comes in handy. We will study about this today.

The word "Simunition" is actually a trademark that was registered by SNC Technologies Inc. (now part of General Dynamics - Ordinance and Tactical Systems Canada Inc). The word is derived as an abbreviation from "Simulated Ammunition". The technology was invented in the 1980s, with the goal of providing more realistic training to military forces.

There are actually many types of simunition rounds. Some of these types are lower pressure rounds and therefore require the standard firearm to be modified with a conversion kit to properly cycle simuntion rounds. The conversion kit is very easy to install and does not alter the weapon permanently -- it can be easily removed after the training exercise is over, which is a very handy feature to have.

The most common simuntion round is the Simunition FX, such as the examples shown above. These come in common calibers used by police and military forces, such as 9 mm. Luger and 5.56 mm. NATO. The bullet is actually a thin case filled with a colored, water-soluble chemical paste. Upon hitting a target, the bullet bursts and the colored paste spreads on the point of impact. This allows the trainers to determine who has been hit and how potentially lethal the hit would have been, if a real bullet was used. The paste is a biodegradable material and easily washes off with soap and water, which makes cleanup after an exercise easy. This technology is heavily used by the US Marine Corps for training purposes (The Marines refer to it as SESAMS (Special Effects Small Arms Marking System)). US Navy SEALs are also known to use simunition in their training exercises.

There are other simuntion rounds used for various other purposes, such as the Securiblank (for firing blanks) and CQT rounds (for close-quarter situations) and even a training grenade, designed to be fired out of an M203 grenade launcher.

Sale of simuntion is currently restricted to military forces, law enforcement agencies and a list of approved security training companies. The price of simunition rounds is also more than real ammunition. Unlike paintball rounds though, simunition allows the user to use the same weapon that they would normally carry into combat, thereby producing a more realistic training scenario.

Parts of the Firearm: The Barrel

In our previous post, we studied the bolt carrier group. In this post, we will study about the barrel of a firearm. We've actually talked a lot about barrels in a number of posts in the past, but never really discussed the parts of a barrel in detail. We will do that in this post.

A barrel is simply a tube through which a bullet comes out of. Most firearms these days have a single barrel, though shotguns do come in double barrel versions. This is in contrast to previous centuries when multi-barrel firearms did exist. In most cases, the barrels are cylindrical tubes, but there are also polygonal barrels and oval barrels which have been used in history. With that said, let us discuss the various terms that describe barrels.

Bore: This is a word that describes the inside of the barrel tube. The inside surface may be rifled (more modern) or smooth (i.e. smoothbore, which is what the first firearms were like).

Breech: This is the rear part of the barrel (i.e.) the end that is closest to the firing mechanism. Most modern firearms are loaded via the breech end of the barrel.

Chamber: The chamber is at the breech end of the barrel. This is the area where the cartridge is placed into, prior to firing it. The most pressure exerted on the firearm upon firing occurs in the chamber area, hence the walls must be thick enough to withstand this pressure. The manufacturing of the chamber has a lot to do with the precision and reliability of the firearm. If the chamber fits the cartridge very tightly and precisely, then accuracy of the firearm is improved, but the reliability of feeding a new cartridge into the chamber is reduced. Conversely, if the cartridge fits the chamber loosely, then the feeding of a new cartridge into the chamber is much easier, but when the cartridge is fired, it will move around in the chamber and affect the accuracy of the bullet. Therefore, a good chamber design tries to strike a balance between these two factors.

An exception to this are revolvers, which have multiple chambers in a separate cylinder. In this case, the chambers are not part of the barrel.

Freebore: In the case of rifled barrels, this is the area just forward of the chamber, but before the area where the rifling starts. It is a smooth area that guides the bullet forward where it engages the rifling.

Muzzle: This is the part of the barrel which the bullet comes out from. For early firearms, they were usually loaded via the muzzle end of the barrel. The pressure generated by the burning gases decreases as it approaches the muzzle. Hence, some manufacturers make the walls of the muzzle end of the barrel thinner than the breech end, since it doesn't have to withstand as much pressure and they can reduce the overall weight of the firearm this way.

Devices such as flash suppressors or compensators may be screwed on to the muzzle end of the barrel.

The length of a barrel depends on the type of firearm. Rifles and shotguns have barrels starting from around 17-18 inches in length and go all the way to 60 inches or longer. Revolvers and pistols tend to have barrels in the 3-5 inch range, though there are exceptions to this rule of course.

When a cartridge is fired, the expanding gases act on accelerating the bullet as long as it is still within the barrel. Once the bullet leaves the barrel, the expanding gases no longer act on it and the bullet is no longer accelerated. Hence, if the barrel is longer, then the expanding gases act on the bullet for a longer time and allow it to come out with greater velocity than if the barrel is shorter. On the other hand, longer barrels are harder to aim with. Hence, the design of a firearm must strike a compromise between these factors.

Cross-sections of three barrel types. Public domain image

In the above image, we see the cross-sections of three different barrel types. The left one is a smooth bore barrel, the middle one is a rifled barrel and the right one is a polygonal barrel.

Parts of the Firearm: The Bolt Carrier Group

In our previous post, we studied the parts of the gun that comprise the fire control group (a.k.a. the trigger control group). In this post, we will study another group of components, the bolt carrier group (or BCG).

The bolt carrier group is usually found in firearms that have a gas operated action. These are the parts that control extracting the old cartridge, cocking the firearm and loading a new cartridge. There are several parts that comprise the bolt carrier group:

Disassembled parts of the bolt carrier group from an AR-15 rifle

In the above image, we see the main parts comprising the bolt carrier group of an AR-15 rifle. There are seventeen parts that comprise the bolt carrier group for the AR-15. They are:

1. Bolt (A)
2. Ejector (B)
3. Ejector spring (C)
4. Ejector roll pin (D)
5. Extractor (E)
6. Extractor pin (F)
7. Extractor spring (G)
8. 3 gas rings (H)
9. Bolt carrier (I)
10. Bolt cam pin (J)
11. Bolt carrier key (K)
12. 2 Bolt carrier key screws (L). These attach the bolt carrier key to the bolt carrier.
13. Firing pin (M)
14. Firing pin retainer pin (N)

There are eight basic operations that are done by the bolt group on an AR-15 or M-16:

1. First, the bolt is in its rearmost position. The action spring then pushes the bolt forward and as it moves forward, it picks up a bullet from the magazine and pushes it towards the chamber via the feed ring.
2. As the bolt carrier moves forward, the bolt passes through cuts in the barrel extension and a cam pin causes the bolt to rotate, so that the locking lugs on the bolt are locked as the bolt reaches its forward most point.
3. When the user pulls the trigger, the sear releases the hammer (we covered these parts in our last post about the trigger group). The hammer spring then rotates the hammer with force into the back of the firing pin (which is part of the bolt carrier group). The firing pin passes through a hole in the middle of the bolt carrier and the bolt and the other pointy end of the firing pin strikes the primer of the cartridge, thereby firing the weapon.
4. Fourth, as the bullet leaves the barrel, some of the gases behind it are tapped into a gas tube. The hot gases travel down the tube, down through the bolt carrier key and are redirected forward, pushing the gas rings on the bolt. This pushes the bolt forward slightly and the bolt carrier to the rear. The rearward movement of the bolt carrier pushes against the cam pin that caused the bolt to lock in step 2. This cam pin now causes the bolt to rotate in the opposite direction and unlock the lugs that were locked in step 2. The bolt is now free to move backwards.
5. As the bolt carrier group moves to the rear, the extractor removes the old cartridge case from the firing chamber and pulls it backwards.
6. As the bolt carrier continues to move backwards, it re-cocks the hammer.
7. As the bolt moving backwards goes past the ejection port, an ejection spring forces the now empty cartridge case to be pushed clear of the extractor and out of the ejection port.
8. Once the bolt has reached backwards to its rearmost point, the action spring pushes the bolt forward again, as described in step 1 and the entire cycle repeats.

The following video gives a decent animation of how things work:

As with the fire control group, it is possible to purchase the parts individually or purchase an entire pre-assembled bolt carrier group part which is ready to be dropped into a firearm. There are aftermarket bolt carrier groups that are plated with hard chrome or titanium nitride for better lubrication and reliability. Some are heavier for slower cycling and others are lighter for reduced loads and faster cycling. Still others are built to much more precise tolerances for consistent locking etc. There is a large selection for users to choose from, depending upon needs and preferences.