7×47mm (seven-four-seven) is the standard-issue rifle cartridge of the Sol Defence Corps, meant as a compromise between previous-generation calibers of 5.56, 7.62 and 6.8. A rimless, bottlenecked cased design, the cartridge uses a durable lightweight polymer casing, a solid-block explosive propellant, and comes with multiple bullet types and pressure configurations for filling diverse roles.
Fulfilling both infantry and specialized roles, 7×47mm can be loaded into standard carbines all the way up to long-distance sniper rifles while retaining its extreme effective range and unparalleled stopping power, bested only by its bigger brother, 11×80mm.
7×47mm ammunition has an effective range of 1.55 kilometers with a 5.3 kilometer maximum range. M74 Standard has a velocity of 1.3 kilometers/second. The bullet is designed for minimal loss of energy over distance, greatly reducing bullet drop and dramatically increasing its effective range compared to predecessor cartridges.
Due to its polymer casing and lightweight propellant, 7×47mm is also much lighter than predecessors, with the whole cartridge only weighing 133gr (8.6g) with a 105gr FMJ bullet - almost 80% of the weight of the round is taken up by the bullet only. This does have the minor downside of making the bullet extremely top-heavy, so the primer base is given additional weight to counteract it.
With extremely high velocity compared to 21st century cartridges as well as a relatively heavy bullet, 7×47mm bullets deliver kinetic energy almost equivalent to .338 Lapua Magnum while retaining less than half the cartridge weight and much better ballistic performance.
Performance
7×47mm, compared to the preceding 6.8×51mm cartridge it replaced, possesses a 35% average increase in velocity and much higher effective range, allowing the new ammunition to be loaded and used as sniper ammunition.
7×47mm M74 Standard penetrates from 41 to 47 cm into soft tissue, while penetrating up to 18 mm of steel plating at up to 900 meters. Fragmentation rounds will always yaw and shatter when entering soft tissue, but is unable to penetrate steel plating at standard range.
With high range, stopping power and excellent weight, it forms the standard caliber as a jack-of-all-trades for most infantry roles against enemy infantry or light mechanized infantry, able to be loaded into sniper rifles, assault rifles, and machineguns alike.
Variants
| Model No. | Type | Weight | Tip Colour | Description |
|---|---|---|---|---|
| M74 | Standard | 105gr | None | Alloy jacket with bismuth core. Standard-issue ammunition designed to perform against unarmoured to moderately-armoured targets. |
| M74T | Tracer | 105gr | Red | M74 Standard variant with red tracer tip. |
| M74AP | Armour-Piercing | 115gr | Black | Alloy jacket with tungsten carbide penetrator. Can pierce up to 35mm of steel plating. |
| M74APSBS | Armour-Piercing Subsonic | 120gr | Black | Short-range subsonic variation of M74AP. Lower pressure than M74AP but fires a heavier projectile, suitable for close combat and optimised for suppressor usage. |
| M74FR | Fragmentation | 108gr | Blue | Polymer-tipped alloy jacket with fragmenting core. Shatters into shrapnel when entering a soft target, causing devastating injury. Optimised against unarmoured personnel. |
| M74HE | High Explosive | 135gr | Magenta | Tungsten carbide penetrator with explosive core. Detonates upon impact with a target or midair via remote. |
| M74IN | Incendiary | 114gr | Bright Orange | Incendiary variant with phosphor charge tip. Upon impact, detonates the charge and sets the target ablaze. Due to its destructive ability, its usage is heavily regulated. |
| M74H | Heavy | 170gr | Red/Black | Brass jacketed M74 variant with red tracer tip. Commonly loaded into machineguns where stopping power is priority. |
| M74MK | Marksman | 112gr | Dark Grey | Match grade M74 variant with higher velocity and much higher accuracy. Used on DMRs and sniper rifles. |
| M74MKSBS | Marksman Subsonic | 118gr | Dark Grey | Reduced range subsonic M74MK variant for usage with suppressed, medium-range sniper rifles. |
| M74MKT | Marksman Tracer | 112gr | Green/Black | M74MK variant with green tracer tip. |
| M74ES | Electroshock | 80gr | Yellow | Nonlethal low-velocity M74 variant that discharges a disabling electric shock to a target upon impact, similar to a taser. Zero penetration capability but can deliver a shock through metal armour. Fielded by Peacekeeper personnel in civilian areas. |
| M74RB | Rubber | 75gr | Black Rubber | Nonlethal M74 concussion variant designed to disable a target via blunt force trauma. Commonly aimed at the legs or arms to swiftly disable a target. Can cause serious injury or death if fired at the head or ribcage. |
| M190 | Blank | 50gr | White | Explosive-only blank cartridge that does not fire a projectile. Used in training. |
| M182 | Dummy | 20gr | White | Polymer dummy cartridge used to test rifle actions. |