Grand Power M4 and M4M – Slovak AR-15 Rifles for Institutional Users
Grand Power is a manufacturer best known on the civilian market for its semi-automatic pistols, which operate on a rotating barrel locking system. However, the company’s portfolio is much broader and, since 2022, has also included rifles based on the AR-15 platform as well as derivatives of the AR-10 system.

At the IWA OutdoorClassics 2022 trade fair, Grand Power debuted its R-15 line of sporting rifles. In the same year, at the International Defence Industry Exhibition (MSPO) in Kielce, the company presented fully automatic rifles intended for institutional users. These were the M4 and M4M models, featuring, respectively, the classic AR-15 direct impingement (DI) system and a short-stroke gas piston system.

Both versions (like their civilian counterpart) can be chambered in either .223 Remington or 5.56×45mm NATO, and they are compatible with standard AR-15/M4 magazines. The main difference between the civilian and military variants—defining both the intended user and the design and finish changes of the “military Freya”—is the capability for fully automatic fire. For this reason, Slovak designers decided to equip the military version with a significantly more durable barrel capable of withstanding sustained fire.
Another difference lies in the upper and lower receivers, which, unlike the civilian version made from milled aluminum, are forged from 7075 aluminum alloy, resulting in a slightly heavier weapon. Additionally, the M4 and M4M are fitted with a dust cover over the ejection port (which was deliberately omitted in the civilian version after consultations with sport shooters). In summary, this variant was created to provide greater reliability and durability in battlefield conditions.
Depending on customer requirements, both models can be manufactured with barrels of various lengths: 11 inches (279.4 mm), 14.5 inches (368.3 mm), 16 inches (406.4 mm), 18 inches (457.2 mm), and 20 inches (508 mm). The rifles are also equipped with fully ambidextrous controls to allow convenient operation.
The military variant was developed in response to reported plans by the Slovak government to replace the outdated 7.62×39mm vz. 43-chambered Sa vz. 58 rifles—currently used by the country’s armed forces—with firearms chambered in 5.56×45mm NATO.
New M4M Variants at IDET 2025
At the International Defence and Security Technologies Fair IDET 2025 in the Czech Republic, Grand Power presented rifles in the new M4M1 variant. According to the manufacturer, the displayed models are already undergoing testing with the Slovak Armed Forces.

According to Grand Power, the M4M1 features modifications to the bolt carrier group and gas system aimed at optimizing weapon performance when using suppressors and improving overall reliability. In addition, the right-side bolt catch and the shape of the handguard have been redesigned. The M4M1’s gas system regulator is exposed, which certainly makes it easier to operate. In the shorter variant, the handguard is shaped to fully enclose the gas block from below and on the sides. In the longer variant, a longer handguard is used, with an access port to the regulator located roughly three-quarters of the way down its length. As expected by modern standards, the handguard features a full-length top Picatinny rail and M-LOK mounting slots. A Picatinny rail has also been added underneath, allowing for quick attachment of selected 40 mm under-barrel grenade launcher models.
Grand Power Also Offers Suppressors
The manufacturer is also involved in the production of muzzle devices, including flash hiders and compatible sound suppressors. The M4M1 rifles were showcased with the TM 556 suppressor model. Openings at the front of the suppressor suggest a design aimed at reducing backpressure—an increasingly popular solution in the market. More details to follow.


More about the product range for uniformed services can be found on the official Grand Power website. The official distributor in Poland is Incorsa.
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