The CQB 9 SBR, and its pistol variant, the CQB 9 Pistol, utilize only premium parts and accessories from the most reputable manufacturers, such as JP Enterprises, Elftmann, and Geissele, to name a few. While most top-tier manufacturers have a few great components to market and attract consumers, ALL of our components are the best of the best. If you disagree, send us note detailing what you would change and why—we will either respond by making the recommended changes or explain why your idea is not feasible. Regardless, if you have a specific component you want replaced, let us know when adding a firearm to your shopping cart and we will make the changes if the request and additional expense, if any, is viable and reasonable.

 
 

Each firearm comes with the choice of not only M-LOK, Picatinny, or KeyMod handguards, but also the option of any of the below receivers. The face of our upper receivers are “squared” and barrels are bedded to ensure precise mating of barrel and receiver for added accuracy.

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Slick Side (standard). Our upper and lower billet receivers are machined from 7075-T6 aircraft grade aluminum. The upper receiver has a machined pocket to accommodate the Magpul BAD Lever. The lower receiver has a precision machined magazine well with beveled feed lip for easy mag swaps and engraved to be compatible with 45- and 60-degree short throw fire control selectors. A tension screw behind the grip screw is able to remove any “slop” between upper and lower. The trigger guard has an integrated large opening for gloved operations.

Side-Charging. Lower is same as Standard. Upper is machined from 6061 billet aluminum. Adjustable tension slide lock on charging handle. Rear dust cover trap door that seals shut when mated with lower. Does not have a machined pocket to accommodate Magpul BAD Lever.

Side-Folding Lower Receiver. The side folding lower receiver features all the great benefits of our traditional 7075-T6 billet lower receiver with the benefit of a folding stock. This option does require a proprietary recoil spring that will result in the elimination of the JP Enterprises Silent Captured Spring if this option is selected. Upper can either be Standard Slick Side or Side-Charging.

6061-T6 and 7075-T6 are two of the most common aluminum alloys around in AR-15 lower receiver use. While 6061 aluminum is a very useful and serviceable alloy, it is not as rugged as 7075-grade aluminum, especially when tempered to the “-T6” designation.

 
 

Detailed specifications

BARREL

If not the most important feature in a rifle, the barrel is one of the most important features. Our 10.5" Supermatch™ 9mm barrels are from JP Enterprises. They are turned from 416R pre-hardened, chromium stainless steel with a 1:10 twist. The barrel is finished in Cerakote, lead lapped, air-gauged for straightness, and cryogenically treated.

 
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By cryogenically treating the stainless steel barrels, there is an immediate increase in barrel accuracy (50% tighter shot group), increased barrel life, increased wear resistance, reduced friction and heat, increased velocity of about 50-60 feet per second, and more rapid dissipation of heat. Many crew-served military weapons (such as machine guns) are fired at their cyclic or rapid rates for long durations, thus becoming more prone to error from their extremely hot barrels. This often may lead to permanent damage of the weapon. After a firearm is cryogenically treated, the likelihood that a weapon will be damaged when firing for extended periods of time is significantly reduced, as shifting and warping of the molecular structure is dampened significantly.

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Each 10.5" barrel comes with a JP Thermal Dissipator™ to prevent heat from building up during sustained fire. This sleeve of anodized aluminum fins hides beneath the handguard and acts as a heat sink to aid in cooling, resulting in a 700% increase in surface area under the handguard to prevent heat from building up during sustained fire. Not only does the Thermal Dissipator keep the operator’s hand cooler, but more importantly, it enhances barrel life.

Want a shorter barrel? We also offer a 6" 9mm fluted barrel made from stainless steel match-grade Shilen blanks with 1:10 twist. While these barrels are highly accurate, they do not come with the added benefits seen in the Supermatch barrels, such as the cryogenic treatment or thermal dissipator. As such, these barrels are not recommended for high cyclic sustained fire.

UPPER PARTS

Muzzle Device. The Lantac Dragon Muzzle Brake offers improved recoil management and muzzle rise over competitors products. Its unique Short Energy Pulse system reduces length of recoil so that repeating shot energy cannot overlap and knock the shooter off target. Full auto fire is possible with massively reduced recoil and muzzle climb, meaning that all shots fall on target.

Charging Handle. The Geissele Super Charging Handle (SCH) is 3D machined from a solid block of aircraft grade 7075-T6 aluminum. Its ambidextrous design allows for seamless operation from either side of the weapon. The levers are dual contoured similar to that of the charging handle of an M14, where not only the x-axis but also the y-axis receive radius cuts. The handling surface of the lever is also checkered, adding a textured grip aiding to the use when operating with gloves. The heightened rear lip of the SCH aids in mitigating gas blowback to the shooter when shooting with short barreled and suppressed weapon systems.

Handguard. All 10.5" variants have the option of a M-LOK, Picatinny, or KeyMod free-float handguard. The M-LOK handguards have seven (7) sides M-LOK technology at the 3, 6, and 9 o’clock positions, as well as the upper and lower 45 quadrants, and a M1913 Picatinny rail at the top. The KeyMod handguards have seven (7) sides KeyMod technology at the 3, 6, and 9 o’clock positions, as well as the upper and lower 45 quadrants, and a M1913 Picatinny rail at the top. The Picatinny handguards have M1913 Picatinny rails at the top and 3, 6, and 9 o’clock positions, and diamond shaped heat vents. All handguards are made from 6061-T6 aluminum animate black hardcoat anodized to MIL-SPEC or better.

For the 6" barrel, we utilize a 5.5" slim free float handguard, available in M-LOK or KeyMod. Like YHM, the M-LOK and KeyMod versions both have has seven (7) sides M-LOK/KeyMod technology at the 3, 6, and 9 o’clock positions, as well as the upper and lower 45 quadrants, and a Picatinny rail at the top (13-slot). These handguards are precision machined from 6061-T6 aircraft grade aluminum with a matte black hardcoat anodize finish.

Unsure what to get? Go with M-LOK! After tests conducted by NSWC-Crane against other rail systems, the U.S. Special Operations Command went with M-LOK due to its superior performance. Repeated installation of the same rail in the same location experienced a point of aim shift of 1.3 MOA, which was less than other systems tested. Drop tests and load tests found M-LOK eventually failed but only at much higher loads than comparative rails.

We also included the Magpul AFG Angled Foregrip to assist with quick sight acquisition and reduce muzzle rise. The AFG’s ergonomic shape is designed to allow the shooter to have a firm hold of their weapon while firing and have an even distribution of weight pushing against the wrist and arm to allow better control of recoil and faster follow up shots. The AFG has horizontal grips to avoid sweat buildup and a low profile to keep it out of your hand’s way as much as possible. Best yet, you do not need retraining with this foregrip—can still rely on muscle memory and grip is as you would the handguard.

LOWER PARTS

Lower Parts. The lower receiver incorporates MIL-SPEC precision machined lower parts but with an emphasis in four critical areas. First, stainless steel anti-walk pins for the hammer and trigger are included. Second, an ambidextrous safety selector that can be changed switched between a short throw 45-degree or a traditional 90-degree setting. Third, the Magpul B.A.D. Lever (Battery Assist Device) allows for quick reloading and malfunction clearance by extending a paddle to the right side of the weapon, allowing manipulation of the bolt stop from the fire control/ready position with the right-hand trigger finger (B.A.D. lever not available with side-charging receiver). Functional for also the “wrong-handed” shooter, the B.A.D. Lever also provides an oversized traditional bolt catch to assist in the fastest possible reloads with either thumb or palm engagement. Fourth, the trigger . . .

Trigger. The Elftmann ELF Tactical Service Trigger has been built for law enforcement and military duty. It is the only AR-15 trigger using aerospace grade sealed bearings, making for an incredibly smooth and fast trigger pull. Elftmann’s exclusive .043 double double wound polished piano wire hammer spring ensures full ignition of any ammo including .308 and 7.62x39. The entire travel distance was measured at 1.75 mm. The trigger pull ranges from 4 to 7 lbs. and is adjustable from the top just by opening the upper receiver and using a hex key. The amazingly short takeup, glass-rod crisp break and next to zero over-travel can be compared to the finest custom 1911 triggers. Below is a video showing the trigger pull, travel distance, and trigger reset.

 
 

Grip. The Magpul MIAD (MIssion ADaptable) GEN 1.1 Grip features removable and replaceable front and rear straps for a custom fit over multiple hand sizes and a removable inner core that holds an included 1/2 oz. reusable lubrication bottle. The inner grip can also hold a Gerber Short Stack weapons maintenance multi-tool and extra cores can be purchased to hold an extra bolt and firing pin, CR123A battery storage, or AA/AAA batteries.

Stock. With the B5 Systems Enhanced SopMod Stock, which was the official pick of the U.S. military, you don’t have to worry about wobble, slippage, and improper cheek weld. Features a fixed sling mount and an overmolded steel anti-rotational QD mount. The B5 SopMod has two water-tight storage compartments for your front sight adjustment tool, extra batteries, carbon scraper, etc. In order to eliminate rattle of any items within these compartments, we suggest including earplugs in there as well.

For our pistol variants, we utilize the SB Tactical SBA4 pistol stabilizing brace, which features an integral, ambidextrous QD sling socket. No more pistol buffer tubes—this stock accepts MIL-SPEC carbine receiver extensions.

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Buffer Tube. The 6-position AR-15 buffer tube is machined from 7075 T6 aluminum to MIL-SPEC dimensions with a Type III, Class II hard coat anodized finish. It also has over-the-breach drainage holes to allow water to be evacuated in submerged environments. The castle nut and QD end plate are machined from high carbon steel, heat treated for extra strength, and given a nitride finish for durability and corrosion resistance.

Buffer Spring. The JP Enterprises 9mm AR Enhanced Silent Captured Spring (“SCS”) eliminates the ‘ting’ sound you hear in the buffer tube when firing suppressed. The 9mm Silent Captured Spring is a drop-in component that softens recoil and reduces cycling noise and vibration in your 9mm carbine. The result is a refined rifle that’s a pleasure to shoot. Paired with the 9mm bolt assembly (below), you have the most reliable 9mm operating system available. The 9mm Enhanced Version has a slightly increased overall bolt mass with more room for increased weight if needed. The result is the heaviest, most reliable 9mm operating system that dramatically reduces bolt bounce while improving accuracy, with softer recoil thanks to a further delay in blowback.

Bolt Assembly. The second generation JP Enterprises Enhanced 9mm Bolt Assembly eliminates the need for a central mass (slug) to readily function with the 9mm JP Silent Captured Spring (above) without compromising bolt weight and reliability. For comparison, this bolt assembly is heavier than the Rock River Arms 9mm bolt with its central mass removed. When used in conjunction with the Silent Captured Spring, the complete JP 9mm operating system is slightly heavier than the complete RRA bolt and buffer, some of the bolt mass having been transferred to the SCS.

LUBRICATION

Know of any other manufacturer that discusses the lubrication they use on their firearms? MIL-COMM is the only brand that supplies extreme performance weaponry lubricants to all branches of the U.S. Military, including U.S. Special Forces, or to more than 20 U.S. allies militaries worldwide, or to nearly all leading Federal, State, and local law enforcement agencies. MIL-COMM’s world renowned TW25B offers all of the below features and benefits:

  • Optimizes performance by providing long-lasting lubrication and corrosion protection.

  • Performs dependably in all climates, under all weather conditions.

  • Greatly reduces friction and wear; extends the life of parts.

  • Proven superior in sand, salt water, and humidity.

  • Repels sand, dust, grit, dirt and debris.

  • Resists wash-off, wear off, burn-off and evaporation.

  • Reduces time and frequency of maintenance events.

  • No known shelf-life.

Will all of these powerful characteristics, it would be wrong for us to not use TW25B.

Due to part availability, specifications are subject to change without notice. In the event a part becomes unavailable, SOF Arms maintains the right to determine which replacement part of equal or greater value will be used.