It is safe to say that the story of the 300 AAC Blackout cartridge will go down as one of the most successful new cartridges in this decade. The 300 Blackout, or 300 BLK, started with a request from a special missions unit within the United States military. The goal was to adapt a .30-caliber cartridge to the M4 platform with minimal effort.

A second requirement was to provide the operator with one rifle that could meet multiple mission requirements. Subsonic ammunition would allow the 300 BLK to be a quiet and effective CQB platform while delivering a .30-caliber, 220-grain projectile to the target. By changing to a supersonic round, the operator could have a fully capable battle rifle effective to 300 yards.

Blackout Basics

The 300 Blackout, or technically the 7.62x35mm, has the same rim dimensions and cartridge taper as the 5.56mm NATO. This is a critical requirement in order for it to utilize the existing mil-spec 5.56mm bolt and feed reliably from a standard 5.56mm magazine. The configuration allows a standard 5.56mm M4 to be converted to 300 Blackout by simply changing the barrel.

While developed for the military community, the 300 BLK offers a great deal of versatility for the law enforcement community. The subsonic loads are ideal for a tactical entry team and provide improved ballistics over the 9mm and the 5.56mm. In addition, when properly suppressed, the 300 BLK is no louder than an air rifle. Changing to a supersonic load gives the rifle an extended-range capability that is well within normal law enforcement operating parameters. In addition, the 300 BLK cartridge works exceptionally well in carbines with shorter barrels and those non-NFA, AR-platform weapons with 16-inch barrels.

Collaborations like the 300 BLK, while common in the defense industry, are less common in the commercial firearms market. Recently, however, New Evolution Military Ordnance (NEMO) Arms and Gemtech partnered up to produce an exceptional suppressed carbine. NEMO Arms has long been known for its advanced weapon designs and technologies. Likewise, Gemtech has long been a leader in the suppressor industry.

Battle Light 1.0 MS

NEMO’s new Battle Light 1.0 MS rifle is chambered in the ever-popular 300 Blackout and was specifically designed to run the new Gemtech GMT-300 -suppressor. This pairing ensures 100-percent reliability when running both supersonic and subsonic ammunition without any adjustments. Essentially, this allows the Battle Light to be extremely effective with subsonic ammo in a CQB environment without compromising its mid-range capabilities with supersonic loads.

The Battle Light 1.0 MS is based around NEMO’s billet aluminum receiver set, which is machined to exacting tolerances. The threaded, 7.5-inch barrel is made from 416 stainless steel and is coated with a nitride finish. The barrel has a 1-in-7-inch twist and is encased in a free-floating, 12.2-inch NEMO handguard that allows for the installation of individual rail sections to add mission-critical accessories. The bolt carrier group is nickel-boron coated for enhanced reliability and ease of cleaning. NEMO also equips the upper receiver with a BCM Gunfighter charging handle.

The lower receiver has an integral, enhanced triggerguard as well as finger grooves on the leading edge of the magazine well. The operating controls are standard issue, with no added ambidextrous levers. In keeping with its quality components, the Battle Light 1.0 MS features a 4-pound, single-stage Timney trigger that is clean and crisp. A Magpul STR stock with a single-point sling attachment and a Hogue pistol grip round out the lower assembly. The entire rifle (as well as the optic and mount) has been coated in Kryptek Highlander Cerakote from MCM Firearms.

NEMO set up my sample Battle Light 1.0 MS with a Leupold Mark 4 MR/T 1.5-5x20mm optic that is equipped with M2 knobs and a mission-specific 300 BLK reticle. This reticle design provides the user with ballistic solutions for both subsonic and supersonic ammunition. A 5-MOA circle surrounds the 1-MOA center dot for both precise and rapid target engagements. Two sets of horizontal stadia lines provide holdovers for the two different loads. The lines on the left side are calibrated in 50-yard increments for subsonic ammunition while the lines on the right side are calibrated in 100-yard increments for supersonic ammunition. When properly zeroed, the center point of the scope’s reticle is the 50-yard point of aim/impact for subsonic ammunition.

Gemtech Tour

In 2014, Gemtech launched a new line of user-serviceable suppressors that utilize its “G-Core” monocore baffles. The GMT-300 is an all-titanium suppressor that features the new G-Core baffle. Unlike some .30-caliber suppressors, the GMT-300 is specifically designed for the 300 BLK round and is full-auto rated. The tube is 6.7 inches in length and 1.5 inches in diameter. Due to its titanium construction, the GMT-300 weighs a mere 14 ounces. The GMT-300 threads directly onto the barrel, under the handguard, and extends some 2 inches beyond the end of the handguard. This effective and compact design makes the GMT-300 ideal for the NEMO Battle Light 1.0 MS carbine.

Extended delays with NFA transfers prevented me from receiving a NEMO/Gemtech package in a timely manner. As a result, Casey Foster, Gemtech’s director of special projects, invited TW to the company’s facility in Boise, Idaho, to test the rifle and suppressor. The company is currently in a transition phase and awaiting the completion of a new manufacturing facility. The rapid growth of the company, and the need for a new building, is directly related to Gemtech’s market share. Like other manufacturers, in the past several years Gemtech has benefited from the tremendous growth in the suppressor industry.

Stepping into the company’s weapon’s vault, I noticed a number of “non-standard” items. One item was the Gemtech Aurora suppressor. The Aurora is a subcompact 9mm suppressor that is designed for government operations where the primary concern is deep-cover concealment. Being only 3 inches or so in length, the Aurora uses a series of nylon wipes instead of baffles and is only effective for 10 rounds or so. While this is “old school” technology, it is the most effective design for maximum sound suppression in an ultra-compact suppressor.

During a trip to a local range, I had an opportunity to shoot an Aurora on a Glock 19, while not as quiet as a Tundra or GM-9, the little unit’s effectiveness was impressive. Given the BATFE/NFA regulations on suppressor components, the Aurora is only available to government agencies.

Strike Silently

Gemtech has been developing effective 300 BLK loads for several years. To test the carbine and suppressor, we used three Gemtech loads, a supersonic 120-grain Ballistic Tip round, a subsonic 187-grain Ballistic Tip round and a subsonic 220-grain Open-Tip Match (OTM) round.

I was very interested in the sound-reduction capabilities of the new GMT-300 when paired with the NEMO Battle Light rifle. We set up a Larson Davis SoundTrack LXT at the prescribed height and distance from the muzzle to record the sound signature. The GMT-300 suppressor proved very effective in suppressing all three loads. The supersonic 125-grain Ballistic Tip averaged 2,060 fps with a sound level that averaged 139.88 decibels. The 187-grain subsonic load averaged 930 fps with a sound signature of 135.46 decibels. The 220-grain OTM load averaged 930 fps, which is approximately 60 fps slower than the comparable Remington load. The 200-grain load measured 133.62 decibels.

Due to range limitations, accuracy testing was completed after I returned home. The fine folks at NEMO built be an upper to the same specifications that I installed on my registered SBR lower. The performance chart reflects how the 7.5-inch-barreled NEMO upper performed with PNW 220-grain subsonic, PNW 155-grain OTM and Remington 125-grain Match loads. Overall, the little rifle is more than capable of reaching out past 100 yards with the proper load.

The BLK Advantage

The NEMO/Gemtech kit is attractive for both law enforcement and military units. The compact size, combined with an effective suppressor and a more potent cartridge, offer significant advantages over a typical 5.56mm NATO carbine. In addition, agencies need only to purchase a barrel and gas system to convert existing rifles to 300 Blackout. While originally designed around a PDW-sized platform, the 300 Blackout also works well in 16-inch-barreled carbines, which can actually be quieter than SBRs when using subsonic ammunition.

The limitations of the 5.56mm NATO cartridge have been well documented in both law enforcement and military publications. While modern loads, such as the excellent Hornady TAP line of cartridges, offer a significant improvement over military ball ammo, the caliber is still limited by diameter and weight restrictions. Loads for the 300 BLK vary from the light 110-grain Ballistic Tip to the heavy 220-grain subsonic rounds.

The story of the 300 BLK is just starting to be fully written. With continued ammunition development, the cartridge has tremendous potential in both law enforcement and military units. Both the NEMO carbine and Gemtech GMT-300 suppressor represent the “best in class” and are worthy of consideration. For those who do not want to go the NFA route, NEMO offers the same configuration in a 16-inch-barreled version.

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