Picture: BR-18 unsupported rifle. It can be seen from this figure alone that the designer has spent a lot of thought on man-machine efficiency and tactical scalability.
In the development of firearms in recent years, several of the most important countries in the world with unarmed equipment have begun to return to the route of armed rifle. Moreover, in the international firearms market, the best new rifles sold in recent years include the AR family (M16 rifles belong to this family) including the HK416, the SCAR rifle series of the Belgian FN company, and the CZ805 series of the Czech CZ company. And so on, they are all supported products. But Singapore’s gun R&D is an exception. It was a user of M16 in the early years. After the mid-1990s, it developed its own SAR-21 unsupported rifle. Its latest generation product, BR18, still adheres to the unsupported rifle route. The characteristics of Singapore's unsupported rifle come from its national conditions-it is a country with all the people and only one city. Once the war comes, apart from a limited number of active military personnel, all the other mobilized participating forces will be ordinary citizens who have not been trained in shooting for a long time, and their ability to shoot and maintain firearms is very low.
From SAR-21 to BR-18, Singapore’s rifle development experience is from creating a product that "amateur soldiers can make do with more accurate shooting", and then develop to "being better." A product that takes care of both amateur and professional soldiers.
Picture: M16A1 rifle Singapore summarizes the experience of using M16S1 (licensed production M16A1) and summarizes some disadvantages of the country; later SAR-21 and other rifles are mainly established to address these problems The overall design ideas: 1. M16S1 adopts traditional target-hole mechanical sights. It is necessary to master its zeroing and aiming skillfully, especially the rapid aiming accompanied by huge psychological pressure under actual combat conditions, which requires a long time of training.
Picture: It is not easy to master the three-point and one-line aiming of the target hole
Picture: It is troublesome to zero the mechanical sights 2. M16S1 After receiving the rifle, the sight must be reset to zero before it can be shot accurately. But for Singapore, the outbreak of war and the mobilization of the whole people may only be overnight or even a few hours. The zeroing process of the rifle requires a certain amount of ammunition, which is not worth mentioning; the key is that the soldiers who are temporarily mobilized will most likely not have time and shooting venues to zero-calibrate the rifle. 3. The M16S1 rifle has a larger overall length. Although the weight of the full gun is very light, for some Singaporean "Strawberry" soldiers who are short in height and lack of exercise leading to significant lack of upper limb strength; the M16S1 will have a center of gravity that is too forward to operate the firearm well.
Picture: Air blowing principle
Picture: The automatic principle of AR15 family determines that it is easier to deposit residues and lose lubricity, requiring stronger cleaning and Lubrication can keep the weapon reliable.
4. The daily maintenance and complete decomposition and maintenance of the M16S1 rifle have higher requirements for soldiers. The air blowing principle of the gun causes the high temperature gas to carry the residue of the gunpowder burning to wash the gun, causing the lubricating oil to quickly deteriorate and evaporate, and the residue is accumulated in large amounts. Therefore, frequent cleaning of the gun is required to maintain good reliability. In addition, in the process of complete disassembly, there are many fragmentary parts such as small bolts and small springs; unskilled soldiers need a long time, and it is easy to lose parts and cause firearms to malfunction.
Picture: SAR-21 rifle
Focusing on these four issues, Singapore chose the unsupported layout to cater to the height in the demonstration of the SAR-21 rifle program in the 1990s. Soldiers with insufficient upper limb strength; optical sights replace mechanical sights, and integrate laser pointers in the handguards, thereby simplifying the soldier’s aiming process to the greatest extent; the sights adopt a very simple and sturdy structure and do not require any extra after leaving the factory. Measures to zero, adjustIt's also very simple.
Picture: Note that the SAR-21 bolt action is a typical M16 style + long stroke piston rod. In addition, its fixed-magnification optical sight and the barrel are rigidly connected, and the gun does not need to be recalibrated for maintenance.
Picture: AK47 also uses the long-stroke piston principle, but because it is not adjustable, it always uses excessive gas to push the bolt to ensure reliability, so the recoil and accuracy become very bad. Inside Structurally, the overall design of the SAR-21's gun machine refers to and retains the design of the M16 to inherit its advantages in shooting accuracy and ensuring that the gun body is not stressed (the gun machine is directly locked into the barrel). But what drives the SAR-21 bolt is no longer the gas from the gas blowpipe, but the adjustable long-stroke piston similar to the Sigma 550 rifle-under normal circumstances, the pores are small, and the gas to push the bolt is less, and the fire The speed is low and the recoil is small; in harsh environments, the air holes can be enlarged, and more gas can be used to drive the gun back and forth, which can overcome the jamming caused by foreign objects such as mud and sand in the gun to a certain extent.
Picture: SAR-21 can easily open the air guide piston adjustment device for cleaning, which is a design point that it pursues easier to maintain than M16S1. But this design also makes it easy to unlock accidentally, causing firearms to malfunction.
In order to further reduce the recoil force, so that the lack of training soldiers can also effectively control the firearms, the SAR-21 rifle has also taken measures such as lengthening the recoil stroke of the striker to further reduce the rate of fire to 450-650 rounds per minute. ; Its rate of fire under normal conditions (450 rounds/min) is 75% of the common design value of other rifles. The adjustment of the rate of fire is realized by a gas regulating device. But for many reasons-such as Singapore's lack of independent firearms design experience accumulation, such as the inherent flaws of unsupported layout; SAR-21 has some problems that have not been resolved, which in turn became the starting point of the BR-18 rifle design. These defects mainly include the following points, some of which also appear on China's 95/97 rifles:
Picture: The button in the red circle is insurance, and the button in the basket is switching Single shot, burst
1. The right hand holding the small grip cannot be used to control the speed machine, but the left hand must be used to press the speed machine backwards and from both sides of the bottom of the butt. Choose single shot or continuous shot. Sending; the switching response of single and continuous sending is very slow. 2. The speed of changing the magazine is slow. In addition to the inherent inconvenience of the rifle without a support, it is also related to the lack of quick release of the gun while the gun has an empty warehouse and hangs up.
Picture: The AUG shooter hits his left shoulder and shoots, his face cannot stick to the butt of the gun, and he can’t get the gun and aim properly.
3. The shell window moves back, making it difficult to shoot against the left shoulder. At this time, if the shooter wants to complete a reliable aiming action, he must tightly fit his face on the butt and block the ejection window, causing the gun to jam; if the face is removed and the ejection space is allowed, it will not be effective. Aiming. This function is not very necessary for general troops, but for special forces, it is almost unacceptable. Because special forces often have to perform indoor and street combat tasks, they often have to reach their left shoulder to shoot. 4. Since the firing pin and the firing pin release structure are moved to the bottom of the butt, and the trigger is in the middle of the gun; therefore, in the firing mechanism without a torch, the trigger often needs to be extended by components such as pull rods, and the rigidity of the components is Factors such as clearance can easily lead to deterioration of shooting feel. The SAR-21 trigger has obvious problems such as long stroke, softness, and unclear firing threshold. 5. The pull handle is set on the top of the receiver. In order to leave enough space for the fingers to pull the pull handle, the aiming baseline is raised and the exposed area of the head is enlarged. On the whole, the SAR-21 rifle is a weapon that is very suitable for soldiers who lack sufficient training to quickly get started, but it is not suitable for more demanding occasions-such as elite units such as special forces, which are used in urban environments. Street fighting and indoor close combat. These combat missions require the guns to have flexible attachment selection and installation capabilities, quick magazine replacement/gun loading capabilities, and flexible left and right shoulder shooting capabilities.force. But in the past 20 years of global actual combat, the infantry in developed countries has faced most combat tasks of this type.
Picture: The core design of the BR-18 has been completely different. The basic structure design of the original SAR-21 rifle determines that its improvement potential is limited; this leads to Singapore’s Introduced the BR-18 rifle with a completely new design to meet more professional combat needs with a brand-new structure. And to a large extent, BR-18 abandoned many of the original SAR-21 design ideas.
Picture: BR-18 bolt camera BR-18 still uses the adjustable long-stroke piston air guiding principle, but its bolt camera is no longer M16 style, but one New and unique design. This involves a crucial change, namely the way of shelling. When the mainstream firearms are ejecting the shell, the gun is pulled back by the groove on the right side of the bottom edge of the shell; when it is retracted, the left side of the bottom edge of the shell will hit a protruding structure; , Pull the right side back, the shell will naturally hit and fly to the right and fly out of the ejection window.
Picture: The groove in the red circle is the place where the cartridge case is discharged
BR-18 In order to solve the problem of the shooter's face in the ejection window when the gun is shooting at the left shoulder against the shoulder For the problem of blocking, the front ejection shell design was chosen. Therefore, its bolt action design must be more complicated. After the cartridge case exits from the barrel, it is not thrown directly outside; instead, it is moved to the right side of the bolt action, and then pushed back in the process of the bolt action. It enters the preset guiding holes and grooves, and is pushed forward. The similar front ejection shell-free gun is not without precedent. The Belgian FN company developed the F2000. However, this type of design inevitably has the same problem. The structure of the gun machine becomes more complicated, the action links of ejecting the shell increase, and the possibility of the ejection route being hindered greatly increases, which means that the reliability of the firearm has decreased—— Especially in harsh environments, when foreign objects such as mud and sand enter the shell ejection channel and the inside of the gun.
Picture: After the BR-18's receiver cover is pushed open, the barrel is completely exposed. But compared with F2000, BR-18's ejection route is already very short, so reliability The drop on the top is not so severe. At the same time, the BR-18 has made another enhanced design. The top of the gun is a movable carbon fiber receiver cover. As long as it is pulled back, the entire barrel can be exposed to the outside, which is very helpful for the shooter without using other tools. Under the circumstances, quickly deal with some simple jamming and jamming faults.
Picture: The blue arrow points to the fast and slow machine, the red arrow points to the magazine release button
After solving the left shoulder shooting problem, BR-18 against SAR-21 Other issues have also been effectively improved. For example, on the top of the grip, there are two thumb toggle handles on the left and right sides. The front is the speed machine, which adjusts single shot, burst, and insurance, and the rear is the magazine release switch; whether it is adjusting the function status of the firearm or To replace the magazine, the reaction speed has been significantly improved.
Picture: In the red circle is the quick release button
and the button behind the magazine well is designed as a quick release button, so that the shooter is changing the magazine After that, as long as you press it with your thumb, the gun can be loaded automatically, eliminating the need to pull the gun again. At the same time, the pull handle of BR-18 has also moved from the top of the receiver to both sides; while reducing the aiming baseline and reducing the exposed area of the head, a longer guide rail can be arranged on the top of the clean receiver, which greatly improves the accessories Installation flexibility. Compared with SAR-21, BR-18 gives up the following features: 1. Features directly available after leaving the factory. The design of BR-18 emphasizes the expansion flexibility of accessories, so its default state is to install only the guide rail. The shooter can of course choose the sight flexibly-from mechanical sights, to red dot mirrors, to telescopic sights; but inevitable, the calibration work after the sight is installed cannot be done in advance by the manufacturer. It must be done by the user.
Picture: Singapore is truly a nation of soldiers, but in a gun-controlled society, recruits and reserve personnel cannot have any good military shooting skills. 2. A low rate of fire deliberately set to improve the controllability of firearms, especially the controllability of bursts. The rate of fire of the BR-18 has increased from 450-650 rounds to 650-850 rounds. There is no detailed information to confirm whether Singapore sacrificed controllability in order to increase firepower; or was it the result of having to abandon design measures such as long strokes and being forced to increase the rate of fire in order to meet the reliability of the front ejection design. However, this will inevitably lead to a significant increase in the recoil of firearms, and it will be significantly more difficult for soldiers to control guns for compulsory and reserve soldiers. Conclusion From SAR-21 to BR-18, although the basic layout of the non-handled gun has not changed, the design concept of Singapore has changed greatly. From emphasizing the ability to instantly form a conscript weapon that can be used in the state of mobilization of the whole people, it has become a professional soldier weapon that is more suitable for elite units to perform high-demand combat tasks, but requires higher soldier capabilities and pre-war preparations. In this process, BR-18 had to adopt the rare and complicated front ejection design in order to continue to adopt the unsupported layout. The cost increase brought about by the complexity of design and manufacturing is second. How large is its potential negative impact on reliability, and there is still a serious lack of time verification-this is the key to its success or failure.
Generally speaking, the author highly appreciates Singapore’s launch of the BR-18 unsupported rifle. Many weapon designs in Singapore reflect their own ideas. (Text / Hou Zhijian)
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