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.

Pistols: Machine Pistols

In our previous post about semi-automatic pistols, we noted that while such a pistol is capable of shooting several times before reloading, the user needs to pull the trigger every time to take a shot. Now, we will study another class of pistols, where the weapon fires multiple times when the trigger is pulled and held down: the machine pistol. These weapons are capable of fully automatic or burst fire, unlike the semi-automatic pistols in our previous post. Some of these weapons are also capable of switching firing modes between single shot, three round burst mode and fully automatic modes.

In an earlier discussion about the differences between a rifle, SLR, submachine gun, carbine etc. we noted that submachine guns have similar features to assault rifles (i.e. capable of fully automatic fire, selectable firing modes, detachable magazine etc.), but use pistol ammunition. So then, what is the difference between a machine pistol and a submachine gun? The difference is indeed very hard to define, but it is now commonly accepted that if the automatic design was scaled down from an assault rifle to a weapon that fires pistol ammunition, then it is a submachine gun. If the original design was a semi-automatic pistol that was redesigned for full-automatic mode, then it is a machine pistol.

Some of the early semi-automatic pistols, such as the Luger P-08 and the Mauser C-96 were modified to produce automatic versions, so the concept isn't exactly new. After World War II, the Russians introduced an automatic pistol called the Stechkin VPS, intended to be used by artillery and tank crews. Due to its weight, it was gradually phased out of regular service. Another two examples of a machine pistol would be the Ingram MAC-10 and MAC-11, which we studied when researching straight blowback actions.

One of the main issues with any weapons firing multiple shots (not just machine pistols alone) is the tendency of the muzzle of the weapon to rise when shooting. We already studied the cause of this phenomenon earlier and some ways to counteract this. Most of the early automatic pistols like the Luger, Mauser and Stechkin came with a detachable wooden stock, which could help steady the weapon better to counteract the muzzle rise.

In the 1970s, Heckler and Koch produced the VP 70, which had a very interesting feature:

This weapon had an optional plastic stock that could be attached to the back of the pistol. The selective fire control was located on the optional stock and could select between single shot and 3-round burst modes, as can be seen in the top picture above. With the stock attached, the user could switch between the modes as desired, but if the stock was not attached, the pistol would only fire in single shot mode. The stock provided a higher degree of stability and accuracy and therefore made it easier to keep it pointed on target when firing multiple shots.

Yet another model is the Glock 18, which came out in the 1980s. The Glock 18 is a variant of the Glock 17 semi-automatic pistol, which is capable of selective fire in either single shot or fully automatic mode.

Note that this model has an extended magazine, capable of holding 33 cartridges. It also has a lightweight folding stock. It works around the problem of muzzle rise by having vents in the front of the barrel, which act as compensators and push the muzzle downwards. Glock 18 models are only intended for military use and are not normally available on the civilian market.

In the late 90s and early 2000s, Stechkin VPS pistols made a comeback, mostly used by personal bodyguards and special forces units.

What is the difference between a rifle, SLR, submachine gun, carbine etc.?

A very common question among newbies to firearms history is "What is the difference between a rifle, a sub machine gun, a machine gun, a carbine, SLR, assault rifle etc." This post attempts to point out the differences and name famous weapons of each type.

Rifle: The name "rifle" originally comes from the fact that the barrel of such weapons is "rifled". This means that the barrel has grooves in it to impart spin to the bullet as it comes out of the barrel. This spin helps to stabilize the bullet as it travels through the air and gives it a predictable drift (e.g.) a particular rifle may fire bullets that travel 1-2 cm. to the right every 100 meters on a windless day. This feature allows the user to reasonably predict where a bullet will hit and gives the rifle its accuracy. Earlier firearms, such as muskets, had smooth barrels. Smooth bore weapons were much easier to manufacture than rifles, but lacked in accuracy, as the bullets didn't have stability in the air and deviated in a random direction from the intended target. Therefore, the standard strategy for European armies of that period was to line up men in parallel lines and tell them to all simultaneously open fire at the enemy, because almost no one could reliably hit the enemy that he was actually aiming for. This massed fire strategy worked because some enemy would be hit, even if they weren't the ones that were originally targeted. These days, most modern firearms, even small ones, such as revolvers and pistols, have rifled barrels. Therefore, in modern times, the word "rifle" by itself, implies a firearm that has a rifled barrel, is designed to be fired from the shoulder, is manually fed (i.e. after each shot fired, the user has to manually operate a lever to feed a new cartridge into the weapon) and carries a small number of cartridges internally (say 1 to 5 cartridges). Examples of modern rifles from the early 20th century would be the famous American .30-06 M1903 rifle, the British 0.303 Lee-Enfield, the Mauser M98 etc.

Assault Rifle: In the early part of the 20th century, it was realized by some military forces that most conscripted troops, who were hastily trained in wartime conditions, had less than a 50% chance of hitting a target beyond 300 meters. It was also realized that most infantry encounters occurred at less than 500 meters and rate of firepower was also an important factor in these encounters. It was therefore reasoned that there was no need to give such soldiers a weapon and ammunition capable of hitting targets at 2000+ meter ranges, since most soldiers could not hope to hit a target that far away in the first place. Instead, it was reasoned that it was better to give troops lesser powered (and therefore, smaller and lighter) ammunition to suit the actual ranges that most infantry engagements occurred at and a correspondingly lighter weapon suited to fire this ammunition. With lighter ammunition and weapon, the soldier could carry more ammunition and therefore use a weapon with a higher rate of fire. While the concept was around before World War II, it was the German StG 44 (Sturmgewehr 44) that really popularized the concept. The word Sturmgewehr was coined by Adolf Hitler and literally translates to "Storm Rifle" (the word "storm" being used in the context of "storming a castle" or "assaulting a castle") and the term "assault rifle" is actually a translation of "Sturmgewehr". Even though there were earlier weapons that could be classified as assault rifles, many historians consider the StG 44 as the first to form the concept of modern assault rifles. In these times, an assault rifle is a weapon with the following characteristics:

• Has a rifled barrel (as in the case of the rifle described in the previous section).
• Has provision to be fired from the shoulder, just like a rifle.
• Uses an intermediate powered cartridge. This means that the cartridges are smaller than those used by a regular rifle, but larger than the cartridges used by a pistol. This is one of the key differences between an assault rifle and a regular rifle.
• Is capable of selective fire modes. This means it allows the user to select between firing different numbers of shots each time the trigger is pulled. In semi automatic mode, the weapon will shoot one bullet each time the trigger is pulled. The weapon automatically chambers the next cartridge to fire, but the user needs to let go of the trigger and pull it again to shoot it. In burst mode, the weapon will fire a preset number of cartridges (say 2 or 3) with each trigger pull. In fully automatic mode, the weapon will continue to keep firing as long as the trigger is pulled and there is ammunition. The ability to switch between various modes of fire is a key feature that distinguishes an assault rifle from other types.
• Has a detachable magazine. Most modern assault rifle magazines carry 20 to 30 cartridges or so.

Examples of assault rifles include the AK-47 family, the M16 family etc.

SLR: This is an acronym for "Self Loading Rifle". The term "SLR" is usually used in commonwealth countries. This has some common features with the assault rifle described above. Like the assault rifle, this is also a weapon that has a rifled barrel and is designed to be fired from the shoulder. It also uses an intermediate powered cartridge and has a detachable magazine like the assault rifle concept. The one key difference between assault rifles and SLRs is that SLRs have only one firing mode, the "semi-automatic mode". This means that each time the user pulls the trigger, the weapon will fire only one cartridge. It will automatically eject the fired cartridge, load the next cartridge and prepare the weapon to fire, but the user has to let go of the trigger and then pull it again to fire the next cartridge. This is unlike an assault rifle, which has multiple firing modes and allows the user to switch between them. Examples of SLRs would be weapons like the American AR-15 and the Indian Ishapore 1A1 SLR. The AR-15 is a semi-automatic version of the M16 rifle and the 1A1 is a semi-automatic version of the Belgian FN FAL assault rifle.

Carbine: This is a term used for weapons that are versions of rifles or assault rifles, but with a shorter barrel and lighter weight. Carbines are bigger than pistols, but smaller versions of rifles. In the days of the Wild West, mounted riders preferred a shorter and lighter firearm because these were easier to operate than full sized firearms, when riding. In more modern times, people inside moving vehicles or in close quarter jungle combat, preferred shorter weapons for the same reason. Since carbines have shorter barrels, they lack in accuracy compared to full sized rifles or assault rifles. While they use the same cartridge as their full sized cousins, the shorter barrel also means reduced velocity bullets. Many assault rifles also come in a carbine version. For example, the American M4 (a carbine version of the M16 assault rifle), the Israeli Galil SAR (a carbine version of the Galil assault rifle), Steyr AUG carbine ( based on Steyr AUG assault rifle. The carbine form uses a 16 inch barrel, whereas the assault rifle uses a 20 inch barrel) etc.

Submachine Gun: This is a weapon that shares some similarities with assault rifles, but one key difference is that submachine guns are designed to fire pistol cartridges instead of intermediate cartridges. As a result of this, submachine guns are generally lighter and smaller than assault rifles and are about the same dimensions or smaller than carbines. Since they use pistol ammunition, they also have less recoil and therefore can be fired from either the shoulder, the hip, or even holding it like a pistol. The first weapon to use the term "submachine gun" was the famous Tommy Gun that we studied about earlier. This is a fully automatic weapon that fires .45 ACP cartridges, the same cartridge used by the Colt M1911 pistol. Another famous submachine gun from the World War II era is the British Sten gun, which is also a fully automatic weapon. Modern submachine guns such as the Heckler and Koch MP-5 are capable of selecting multiple firing modes. Submachine guns are more preferred for close-range combat in urban environments because, with lower powered pistol cartridges, there is less risk of bullets penetrating through walls and hitting innocents on the other side

Machine Gun: This generally denotes a weapon that is capable of rapid, fully automatic fire and carries a large supply of ammunition. Fully automatic fire means that the weapon will keep firing as long as the trigger is pulled and there is a supply of ammunition available to it. Most machine guns fire either full sized or intermediate sized ammunition, similar to rifles and assault rifles. Machine guns generally carry a large supply of ammunition in ammunition belts, drum magazines or box magazines. This means that they generally have hundreds of cartridges available to them, unlike the 20-30 cartridge magazines used by assault rifles. They are also generally heavier than rifles and assault rifles. Examples of machine guns would be the Gatling Gun, the Gardner Gun, the Bira gun etc. Modern machine guns include the Browning Automatic Rifle (BAR), the British Bren gun, the American Stoner 63, the Belgian FN Minimi etc.

Actions: Blowback Action: Roller Delayed Blowback

In our previous post, we studied the basics of the blowback action and learned a few things.

1. Blowback actions do not have the bolt locked in place at the moment of firing. Instead the bolt is held in place by inertia and springs.
2. When the cartridge is fired, it is desirable for the bolt mechanism to only start moving backwards after the bullet has left the front end of the barrel and the gas pressure in the chamber has dropped to a safe level. This is because: (a) a tight gas seal must be maintained until the bullet has left the barrel for greater range. It wouldn't do to leak gases out of the back end and reduce the pressure in the barrel while the bullet is still inside the barrel (b) It is not good for high pressure gas to blow through the magazine area and out the ejection port and rearrange everything inside the gun on the way out.

Therefore, there must be some method used to delay the backward movement of the bolt after the cartridge is fired.

As we saw in our previous post about straight blowback actions, one way to achieve this is to use a bolt that is much heavier than the bullet and use a stiff spring to hold the bolt in place. That way, when the high pressure gas acts on the bolt, it does not move much right away because of inertia. By the time the bolt and fired cartridge case start moving backwards, the bullet has already left the front of the barrel along with a lot of the high pressure gas, the pressure inside the chamber has already dropped to a much safer level and the bolt and cartridge case are moving back mostly due to momentum. Unfortunately, this makes the weapon much heavier than normal and harder to cock initially, as the user has to apply much more force to move a heavier bolt and stiff spring. Therefore, weapons that use straight blowback tend to use smaller and low powered cartridges to be suitable for practical usage by normal users.

Another alternative is to develop some kind of mechanism where the bolt encounters some higher resistance when initially trying to move backwards. This ensures that the bolt is delayed from moving backwards immediately after the cartridge fires and it doesn't move until the bullet has left the barrel. The idea is to put the bolt under some kind of mechanical disadvantage, so that much more force is required initially to move the bolt backwards. With such a mechanism, there is no need for a heavier bolt or stiffer spring and therefore the whole weapon can be lighter. Conversely, the weapon can also fire higher powered cartridges since the weight savings gained by a lighter bolt can be used to make the barrel heavier and breech mechanism stronger.

One way to do this is to use rollers to delay the bolt. Such an action is called roller delayed blowback. The most well known weapons that use this action are the Heckler & Koch G3 rifle and the Heckler & Koch MP-5 submachine gun.

The history of this type of action dates back to the middle of WW-II when it was used for an MG42 derivative and the Mauser StG 45. After the war, Mauser's factories were taken over by the French government and reorganized under a French organization called CEAM. Two of the former Mauser engineers, Dr. Ludwig Vorgrimler and Theodor Loffler were employed by CEAM and together perfected the roller delayed blowback design. Although they perfected the design based on the Mauser StG 45 cartridge (7.65 x 35 mm.), the French military then wanted to use a US designed .30 cartridge instead and so they were told to redesign for the new carbine. The French government also got involved in Vietnam by 1949 and therefore cancelled the project for lack of funding. Dr. Vorgrimler later left CEAM in 1950 and went on to join the Spanish company CETME, where they had already recruited some other former Mauser workers, as well as some others from another major German weapons manufacturer from world war II, Rheinmetall GmBH. Therefore, it was CETME that released the first commercial rifle using roller-delayed blowback, rather than CEAM. The post-war West German government was interested in the CETME design and licensed it for manufacture by Heckler & Koch and Rheinmetall. The result was the development of the Heckler & Koch G3 rifle. Dr. Vorgrimler was later employed by Heckler & Koch in the 1960s and went on to develop many more successful designs including the MP-5 submachine gun, which is still used by many forces worldwide.

The principle of the roller delayed blowback is to use two small masses (i.e. the rollers) usually attached to the bolt and arranged so that they move at nearly right angles relative to the bolt, at the moment of firing. The roller mechanisms act like levers and effectively multiply the mass of the bolt and bearings, which means that greater force is required to move them. The extra mechanical work that must be done to overcome this force generally allows the pressure in the barrel to fall to a lower level by the time the bolt starts to move backwards and thus delays the motion of the bolt until the bullet has left the barrel and the pressure has already dropped to a lower level.

The roller-delayed blowback mechanism of a Heckler&Koch G3 rifle. Public domain image.

US Patent 3283435. Drawing of roller-delayed blowback mechanism

When the weapon is cocked, the rollers (5a and 5b in the patent drawing) lock into the recesses in the trunnion (7a and 7b) and the face of the bolt head (4) sits flush against the base of the barrel, providing a tight seal. When the cartridge is fired, the bolt tries to move backwards and forces the two rollers (5a and 5b) against the locking piece (2). The locking piece, in turn, pushes against the bolt carrier (1) and the spring locking lever. The rollers act as levers and effectively multiply the mass of the bolt, which increases the force needed to push the bolt back. Once the rollers are pushed out of the trunnion recesses and are inserted back into the bolt head, the whole bolt assembly can now move backwards much easier. The bolt then moves back against spring pressure from the recoil spring (10) and the empty cartridge case can be extracted and ejected out of a port on the side of the weapon. When the bolt moves backwards to its maximum position, the recoil spring then pushes the mechanism forward whereupon, it picks up the next cartridge to fire from the magazine and loads it into the chamber.

The next figures from hkpro.com also make the concept very clear.

As the bolt head moves backwards, the force is transmitted from the bolt head to the rollers, as indicated by the horizontal red arrows. The rollers in turn, split the forces to the barrel extension and the locking piece, as indicated by the other red arrows. Approximately 75% of the force goes to the barrel extension and only 25% to the locking piece.

The extra force that is need to push the rollers out of the recesses and back into the bolt delays it enough for the bullet to leave the barrel and take most of the high pressure gases out of the front of the barrel. As a result, by the time the bolt starts moving backwards, the pressure of the gases in the chamber have dropped to a much lower level.

Image taken from hkpro.com. Unfortunately their web-server keeps going up and down, forcing me to not link to them directly.

In the above figure you can see the position of the rollers from where the bolt is in a locked and unlocked position. Once the rollers have moved out of the trunnion recesses, the whole bolt assembly moves back easily, just like in a straight blowback system; and the empty cartridge case moves back with it and is ejected out of the receiver.

There are some advantages and disadvantages of a roller delayed blow back system.

Advantages:

• The barrel can generally be free floated, since there aren't any moving parts up front. This is unlike a gas operated mechanism, where part of the mechanism is hanging off one side of the barrel and disturbing the natural harmonics of the barrel. Free floating the barrel increases the accuracy of the weapon.
• Unlike the straight blowback mechanism, this one can use higher powered ammunition.
• When used with suitable ammunition that is designed for the weapon, this is a pretty reliable design.
• Moderately cheap to manufacture.

Disadvantages:

• This design definitely doesn't like wide varieties of ammunition. It is sensitive to factors such as the weight of the bullet or the type of case. Therefore, the ammunition used for this weapon needs to be good quality and manufactured to uniform standards, otherwise it could cause operating issues.
• This is a design that can get dirty very quickly while using. It is fairly easy to clean up though.
• It is a relatively complex system compared to some other designs, such as the AK-47 mechanism.
• The locking delay can go down as the parts begin to wear out, chamber gets dirty or clean etc.
• Cannot be tuned by a user, unlike a gas-operated mechanism with a regulator is.

Though CETME invented the first commercial rifle using this action, Heckler & Koch are the best known users. Several Heckler & Koch products such as the G3 rifle, MP-5 submachine gun, P9 pistol, HK-21 and HK-23 machine guns, SL-6 and SL-7 hunting rifles all use this mechanism. Other users of this action include the Swiss SIG SG 510 rifle and CETME rifles such as the modelo A, B, C, L and LC .

Actions: Bolt Action

In the last couple of posts, we studied the break-open action and the sliding barrel action. Now we will study another type of action that is known for its sturdiness and is still with us. This action is the bolt action.

We actually studied the first weapon to use a bolt action a while earlier. It happens to be the Dreyse Needle Gun. This gun had a number of firsts to its name:

1. It was the first mass-produced military weapon using breech-loading technology.
2. The ammunition it used burned almost completely, so it didn't need to eject the paper casing after firing the weapon. This was a precursor to caseless ammunition.
3. It was the first bolt-action breechloading weapon.

The action was a significantly new invention in 1841, when the Dreyse needle gun was first introduced. It allowed the user to reload significantly faster than the opposition who were still using muzzle-loading weapons (almost 5 times the shooting speed). It also had the advantage that the user didn't need to stand up to reload the weapon and therefore could hide behind cover.

The basic idea of a bolt-action weapon is a manually operated bolt, which is manipulated by a handle, typically on the right side of the weapon. The handle is used to unlock the bolt and open the breech cover. The old cartridge case is then ejected from the breech chamber. The opening of the bolt may also cock the weapon in some models. Then a new cartridge is put in the chamber and the handle is then moved forward to close the bolt. In some models, the action of closing the bolt cocks the weapon. The weapon is then ready to fire.

In some models, opening the bolt causes an extractor lever to automatically pull the old cartridge case out of the chamber to eject it. The magazine has a spring that pushes a new cartridge into the chamber, when the old cartridge case is pulled out by the extraction lever. Such a mechanism is used in many bolt-action rifles, such as the Springfield M1903 rifle which carries a 5-shot magazine under it. This speeds up shooting because the user doesn't need to waste time pulling out the old cartridge or feeding a new one by hand.

Compared to other actions, the bolt-action has a few advantages. It is extremely simple to make, yet has very high accuracy. It is very cheap to manufacture and very light-weight. Best of all, it is a very strong action and can handle powerful cartridges. The only downside to it is that it doesn't support a very high rate of fire compared to some other alternatives. Since most modern military rifles are semi-automatic or selective fire weapons, they don't use this mechanism. However, the simplicity combined with the accuracy and the ability to handle high powered cartridges make it ideal to be used in sniper rifles. In fact, the bolt-action is overwhelmingly the action of choice in most of the sniper rifles used throughout the world. This mechanism is also used in many hunting rifles, where rate of fire is not as important as accuracy and power.

There are three major variants of bolt-action rifles which we will study below.

The Mauser M-98 system was first introduced in 1898 (hence M-98) with the Mauser Gewehr 98 rifle, which was used by the Germans between 1898 and 1935. This highly successful bolt-action design was later used in a lot of other rifles and is the dominant form of bolt-actions used today. In this type, the rifle is cocked when the bolt-action is opened. The Gewehr 98 has a 5-round magazine.

Click image to enlarge

The image above shows an original Mauser model from 1898. The weapon was designed with a lot of thought. The bolt handle is securely attached to the bolt and there are a couple of gas vent holes built into the bolt, so that if there is a rupture in the cartridge case or primer, the hot gases will vent out of the magazine hole instead of near the user's face. The "controlled feed" extractor claw holds on to the cartridge the moment it has fed from the magazine and holds on to it until the cartridge case is ejected. The weapon is cocked as the bolt is opened (actually, it specifically cocks as the bolt handle is rotated upwards, before pulling back to open the bolt) and the rear part of the striker protrudes from the back of the bolt, which allows one to quickly check if the rifle is cocked or not visually. The original mauser design was not given to cheap mass-production.

The cock-on-bolt-opening design was later adopted by other rifles as well, notably the Springfield M1903 (like the one shown in the picture above). The M1903 was used in the US military from 1903 all the way into the Vietnam war. The cock-on-bolt-opening design rifles are slightly slower to load than the other variant which we will study below. However, it is the more common of the two variants of bolt action and is used in nearly all modern hunting rifles today. It was also the dominant form of action used between the 1890s and the mid 1900s.

Another variant of bolt action is the cock-on-bolt-closing design. This is famously called the "Lee Enfield design" as it was first used in the Lee-Enfield rifle of 1895, otherwise known as the SMLE (Short Magazine Lee-Enfield) rifle. This rifle was heavily used in the British Commonwealth and its descendant is still used by Indian police, which makes it the longest serving bolt-action rifle model in existence.

The above is an example of a Lee-Enfield Mark I rifle. In this rifle, pushing the bolt closed cocks the rifle. This makes opening the bolt a lot faster and smoother, compared to the cock-on-opening design of the Mauser. This feature, coupled with its larger capacity 10-round magazine meant that a user could shoot 20-30 times in 60 seconds, making it the fastest bolt-action rifle of its day. The Lee Enfield rifles fire a 0.303 bullet. Note that the 0.303 bullet actually measures 0.311 inches in diameter, as we have noted previously.

The Indian Ordnance board later made a variant of this rifle called the Ishapore 2A1, which was based on the Lee Enfield Mark III rifle model.

The main difference is that the Ishapore 2A1 rifle is chambered to fire a standard NATO 7.62 x 51 mm. round. As a result of this, the steel used in this weapon is also improved to handle the higher pressures of the NATO cartridge. This rifle has the distinction of being the last bolt-action rifle designed to be used by a regular military force (other than sniper rifles, which are for special forces only). It is still used by police in various states in India. It is also popular with civilian shooters in the UK and USA.

The Lee-Enfield cock-on-closing-bolt system was also used on a number of other rifles, mostly made in the UK and other commonwealth countries.

A third variant is the Mosin-Nagant system, which was first used by the Mosin-Nagant rifle in 1895. Unlike the Mauser system, the bolt head rotates with the bolt and lugs, whereas the Mauser has the bolt head is an integral (non-removable) part of the bolt. It is also unlike the Lee-Enfield where the bolt head remains stationary and the bolt alone rotates. It is a rugged design, but is complicated. This type of bolt-action was mostly used in Russia, but one version called the M28 was manufactured by the Finns. The M28 is widely regarded as one of the finest and most accurate military rifles ever produced and was used by the most successful sniper of all time, a Finn named Simo Hayha.

There are other bolt-action systems, but never caught on as much as the above three systems.

Bolt actions are more accurate than semi-automatic rifles, which is why hunters and military snipers still use them. The reason is because when the cartridge is fired, the entire energy is devoted to propelling the bullet out of the rifle, unlike a semi-automatic or automatic weapon, where part of the energy is diverted to eject the old cartridge, auto-cock the weapon and load a new cartridge. It also has less moving parts than most other action types. The only parts that really move in a bolt-action when it is being fired are the spring and the firing pin. This simple and strong design means it can fire magnum cartridges as well. One more advantage for snipers is that it does not eject the spent round automatically, which is beneficial to the sniper because it does not give away his position and he can decide to eject the round himself when it is safe to do so. The only disadvantage is that it is slower to use than some other actions. So, while it may not be as useful to an ordinary infantryman, this action is more valuable to snipers and hunters and has thrived for these reasons even to the present day.