SAR-21

The SAR-21 ("Singapore Assault Rifle - 21st Century") is a bullpup assault rifle designed and manufactured in Singapore. First revealed and subsequently adopted by the Singapore Armed Forces in 1999, it was intended to replace the locally license-built M16S1. Many of its design features are directly intended to counter the weaknesses of the M16 as encountered operationally by some infantrymen.

Design
Made of a rugged, high impact polymer, most of the manufacturing is done utilising CNC machines, with ultrasonic welding for the steel-reinforced receiver halves and the gun barrel being cold hammer forged. It uses a modified Kalashnikov/Stoner operating system, boasting higher reliability and lower recoil. The translucent magazine allows precise assessment of current ammo load.

The SAR-21 is also the first production assault rifle of its class to incorporate a built-in Laser Aiming Device (LAD) (powered by a single "AA" battery) as standard. The rifle incorporates various patented safety features, such as a Kevlar cheek plate and overpressure vent that protects the shooter in the unlikely event of a chamber explosion or catastrophic failure. It also has an integral 1.5x optical scope that is built into its carrying handle. The scope aids in target acquisition, particularly under low light conditions. The scope is factory-zeroed, and requires minimal further zeroing to suit different users. This minimizes non-training range time.

Operation
Like most other weapons, clearing the weapon is accomplished by removing the magazine, pulling the charging handle to the rear, and observing the chamber. After loading a magazine into the well, the weapon is made "ready" by cocking the weapon, and engaging the FN MAG-type safety button. The position of the fire selector button (SEMI or AUTO) may also be adjusted.

The on/off switch for the LAD is on the left handguard; when holding the weapon at ready, the left thumb rests naturally on it.

Like the M-16 rifle, the bolt does lock open on an empty magazine. When the magazine is exhausted, it is removed by depressing the AK-47-style lever. After being replaced, the weapon must be cocked again before the soldier can commence firing. With sluggish operation due to fouling, the gas regulator setting may be increased by turning it with a coin, screwdriver, or any other thin flat object.

History and Development
Since the mid-90s, the Singapore Armed Forces had an outstanding requirement to come up with a replacement for their M16S1. Most of the M16/AR-15s in service have been in use since the 1970s, and the SAF had to either procure newer weapons (thought was given to purchase the M16A2) or to develop their own indigenous rifle.

It was discussed that buying weapons off the shelf would require soldiers to adjust to the weapon, as opposed to a weapon designed specifically to their needs. The rising costs of maintaining the M16s also made it more justifiable to develop a low-maintenance weapon. As a result, the decision was made in 1995 to design and build the new weapon locally.

The Advanced Combat Rifle was thus born. This weapon would be the precursor to the SAR-21.

SAR-21 Light Machine Gun (LMG)
Fitted with an open bolt, it has a heavy 513 mm barrel with an integral folding bipod.

SAR-21 Sharpshooter
Same as the basic SAR-21, but has 3.0x optical sight instead of standard 1.5x sight. The sight picture is composed of luminous black paint, allowing easier target engagement at night without use of the LAD.

SAR-21 Grenade Launcher (GL)
Attached with a CIS 40 mm or M203 grenade launcher. Several sub-variants/prototypes incorporate different targeting modules (or mounted on p-rails) for grenade target acquisition. Known sights to have been used include aiming quadrants, various optical sights (the GLS-203and DNS) and laser fire control systems.

SAR-21 P-rail
Has a Picatinny rail in place of its integral optical sight. Charging handle is moved to the left hand side of the weapon (Interchangeable with right side).

SAR-21 Modular Mounting System (MMS)
Has integral optical sight and LAD removed to allow a wide variety of add-on tactical accessories, such as vertical assault grips, tactical lights and reflex sights. Charging handle is moved to the left hand side of the weapon. Similar to P-rail model with exception of shorter barrel.

SAR-21 Light Weight Carbine
A light weight SAR-21 variant was revealed during the Asian Defence Exhibition held in conjunction with Asian Aerospace 2006. The variant boasts an ultra-short barrel, shorter handguards and an integral holo-dot aiming recticle. A Picatinny rail is used as well.

Criticisms and other issues
Early users of the weapon in the Singapore Armed Forces experienced many problems due to their unfamiliarity with the bullpup design. Their criticisms (usually in comparison with the M16S1 rifles they were already trained with) include:
 * the awkward position of the magazine well, and the difficulty in changing magazines, requiring multiple hand changes
 * the awkward position of the fire selector (located at the butt, with the action), as opposed to the thumb selector on the M16
 * the sluggish trigger pull compared with the crisp trigger of the M16
 * the weight of the weapon
 * the increased muzzle blast, due to the muzzle being nearer to the user's ears
 * being told by instructors that it is a "right-handed only" weapon and left-handed soldiers having to (and are still being taught to) fire with their right hand even though the weapon is ambidextrous
 * iron sights that chipped off easily when weapon was dropped

Some of these criticisms were addressed with design modifications to the later production models. New weapon handling procedures were also introduced.
 * The magazine changing issue was solved with training soldiers to always hold the pistol grip with their master hand. The charging of the weapon and reloading of magazines are to be done by the non-master hand.
 * The sluggish trigger pull was fixed by using a stiff sliding plate in place of the flexible rod.
 * The Steyr Aug styled iron sights were replaced with stocky, hardier ones.

Note: Stemming from the myth that all bullpup weapons can only be fired from one side, a common misconception among SAF soldiers and instructors is that the SAR-21 is a right-handed only weapon.

The kevlar plating on the left side of the weapon butt (where a right-handed user's face would typically be) is effective in protecting the user from any internal chamber explosion by directing the resulting force to the right. However, that resultant force would also seriously injure anyone unfortunate enough to be on the right side of the weapon. In the case of a user firing from his left shoulder, this could cause severe injury to his face.

As a result, all left-handed SAF soldiers are taught to fire from their right shoulder as a safety measure, not because it was designed without left-handed users in mind. In fact, the SAR-21 was designed with an in-built brass deflector to eject its bullet casings forward, thus negating the chances of the spent casings hitting a left-handed user's face and removing the requirement for an entire separate rear assembly to cater for left-hand ejection. This is in contrast with the Chinese QBZ-95 in which PLA soldiers are taught to fire with their right hand only because its design lack both brass deflectors and provision for left-hand ejection of spent casings.

Users

 * 🇸🇬 Singapore - Singapore Armed Forces (primary user) & Singapore Police Force's STAR unit.
 * 🇲🇦 Morocco - Royal Moroccan Army.
 * 🇮🇩 Indonesia - Indonesian Army's Tontaipur, Indonesian Air Force's Detasemen Bravo & Indonesian Navy's KOPASKA special forces unit.
 * Brunei - Royal Brunei Armed Forces.
 * 🇧🇩 Bangladesh - Bangladesh Special Forces.
 * 🇵🇬 Papua New Guinea - Police Forces (on trials)