Mark 24 Special Applications Battle Rifle

A Mark 24 Mod. 0 in low-visibility colors, fitted with a pair of flip-up backup iron sights and an original 10-round “marksman” magazine.

The Mark 24 Mod. 1 Special Applications Battle Rifle, also known as the SABER Weapon System or just the Saber, is a modular air-cooled, gas-operated bullpup battle rifle chambered for electronically-fired 10x45mm cased telescoped ammunition. Intended to fulfill a marksman role between the lighter Mark 15 Adaptive Rifle System and the heavy, specialized Mark 1 Railgun, the SABER is beginning to see use in select TACCOM units.

History

Impressed with the effectiveness of the BR55-series battle rifle employed by some Solas Tempus personnel, Solas Tempus R&D began developing their own interpretation of the concept, a high-caliber select-fire rifle employing a new, novel cartridge. During the development phase, the requirements and testing parameters were constantly changed, clouding the program’s original goal to produce a battle rifle and instead producing a weapon more similar to a light anti-materiel rifle. Nonetheless, impressed with the weapon’s performance, the weapon was adopted and type-classified as the Mark 24 Special Applications Battle Rifle in early 2384, filling an anti-infantry/light armor role where the Mark 15 would be inadequate and the much larger Mark 1 would be too powerful.

An accessory package for TEMPCOM and SPECCOM units, named the Special-Purpose Enhanced Combat Modification package (SPECMOD), was developed concurrently with the weapon, along with a heavier subsonic projectile for when stealth is paramount. The kit is currently finalizing development and will be issued to select TACCOM and all SPECCOM units.

After an intial testing and evaluation period with combat units, the Mark 24 Mod. 1 variant was devised from operational feedback and replaced most Mark 24 Mod. 0 units then in service.

Utilizing 3 months worth of testing and field expertise, the Mark 24 program was cancelled under the pretense that the rifle was overweight, over-complicated, and overpowered for general infantry applications. A project is in the works to bring the Mark 24's special purpose 10x45mm cased-telescoped cartridge to a larger, semi-fixed automatic rifle platform.

Design

Externally and internally, the weapon resembles and borrows significantly from a Tavor X95 assault rifle with an elongated handguard and wider barrel. Unusually for Solas Tempus-produced arms, the weapon is arranged with the magazine behind the trigger group in a bullpup configuration, reducing overall length when compared to traditional layouts. The SABER feeds from 15 or 20-round detachable box magazines, each fitted with a large, exaggerated rubberized baseplate for ease of access when stored in pouches or other load-bearing equipment. The ejection port can be rearranged with minimal tools to accommodate both right and left-handed shooters, and sports a large dust cover to prevent unwanted foreign objects from entering the receiver. An adjustable cheek riser sits above the ejection port, behind a long rail with space for large high-power optics. Protruding from the stock are several raised bumps, each containing a pin that can be removed with a pointed object for easy disassembly.

The trigger is an unconventional bladed-type design, with a pull much smoother than typical bullpup-style rifles.To make the weapon easier to operate with heavy winter gloves or armored gloves on, the trigger guard has been elongated and extends from the handguard to the base of the pistol grip. Above the trigger is the magazine release, which is fitted with a small “fence”, and the ambidextrous fire selector, with options for safe, semi, and 2-round burst. Mounted behind the fire selector, on all new Mod. 1 models, is a thumb-actuated bolt release lever fit with a fence, which replaces the larger bolt release behind the magazine well. The non-reciprocating charging handle is ambidextrous and can easily be swapped out for a strictly left or right-handed version for compactness. Finally, the elongated handguard features a long underbarrel rail, and houses a free-floating 24-inch match-grade fluted barrel as standard. The preferred muzzle device is a quick-detach 3-pronged multipurpose flash suppressor derived from the FOSSA 5.56, which doubles as a compensator to control muzzle rise during sustained fire.

Internally, the weapon resembles the XV-15 ARS, although it uses a long-stroke gas piston operation system instead of a simpler delayed blowback action. Instead of a firing pin, it utilizes a lithium ion power cell to create an electronic impulse capable of setting off the round’s primer in order to reduce the overall amount of moving parts. The battery is located behind the magazine well and can be replaced quickly with the aid of a round or casing’s rim, and the battery itself can be adjusted to modify the burst fire rate. Newer power cells issued with Mod. 1 variants allow for burst fire output adjustments as well, adjustable from 2 to 5 rounds.

The top and bottom rails are designed to accept all standard Solas Tempus combat optics and accessories, including grips, sensors, and bipods. These rails are removable and replaceable with shorter, lighter lengths depending on mission demands, and additional accessory rails can be added to the sides of the handguard.

When equipped with a standard length 24-inch barrel, the weapon measures in at 34.3 inches long overall, and weighs about 10.5 pounds unloaded.

Cross-section and 3D model of an A19 HVAP round. 1) Cross-section of an A19 round 2) Tritanium alloy slug 3) DU penetrator 4) Copper jacket

Ammunition

Ammunition for the weapon comes in the form of 10x45mm polymer-cased telescoped rounds, which utilize highly-efficient compacted propellant to produce high performance in a round that is roughly 40% lighter and 12% smaller than a conventional brass-cased round.

A19 High-Velocity Armor-Piercing

Standard issue for the SABER is the A19 High-Velocity Armor-Piercing round, a 410-grain tritanium alloy-jacketed projectile with a depleted uranium penetrator and tritanium alloy slug. When fired from a 24-inch unsuppressed barrel, the A19 readily clocks in at just over 1,200 meters per second at the muzzle, and is designed to penetrate heavy modern body armor types and light exosuits. Post-penetration damage is assisted by it’s high velocity and yaw-independant nature, where the round will quickly fragment, yaw, and dump energy into the target regardless of angle of impact.

With armor penetration nearing that of small autocannon rounds, the A19 has a significant recoil impulse when fired by the Mark 24. The unorthodox layout of the rifle does little to help this, although it is compensated somewhat by miniaturized internal recoil dampening systems and the muzzle device. As such, it is still very much a specialist weapon, although lighter loads are being developed to allow less-trained personnel to effectively employ the rifle.

Cross-section of an A20 bullet. Note the very distinctive open tip of the round.

A20 High-Impact

Seeing limited production is the A20 High-Impact round, a 392-grain open-tipped tritanium alloy round based off of an ancient projectile design originally intended for long-range competition target shooting. The small hollow cavity within the nose of the round moves the center of gravity back towards the heavier rear of the bullet, causing the round to travel in a more stable and thus more accurate flight pattern across longer distances. This change in center of gravity also has an added effect of lethality against soft or less-armored targets, as while it doesn't expand like a more conventional hollow-point design, the heavier base of the bullet will still yaw around, tumble, and fragment once it strikes soft tissue. Additionally, the hollow nose cone is prone to breaking off entirely on impact, contributing even further to post-penetration damage. When fired from a standard 24-inch barrel, the slightly lighter A20 round travels at roughly 1300 m/s.