2A Armament Balios-Lite Gen 2: If you need an upper for an SBR or pistol build, then check out the 7.5-inch-barreled Balios-Lite Gen 2 5.56mm complete upper. As its name implies, this upper is super lightweight and features a titanium gas block a Gen 2 handguard, a titanium barrel nut and a titanium T3 compensator. It also comes with a full-mass bolt carrier and a BCM Gunfighter Mod 4 charging handle. The complete uppers weighs 2.5 pounds.
Alexander Arms .17 HMR Upper: It’s about time someone made an upper in .17 HMR. Alexander Arms’ complete .17 HMR upper assembly can be had with a whole host of features and options, but the standard model comes with a blowback operating system as well as an 18-inch, stainless steel, button-rifled barrel with 1-in-10-inch twist rate, straight flutes and a muzzle threaded for standard 5.56mm/.223 devices. A six-vent A1 flash suppressor comes installed. The free-floating handguard is a mid-length model made of G10 fiberglass composite. Two 10-round magazines are included, and the upper is compatible with any standard-specification lower receiver.
Axelson Tactical AXE-18: The AXE-18 Combat Upper Receiver Set is compact and would be ideal for an SBR or AR pistol build. This complete assembly includes a forged upper receiver, a BCM gas block, a Centurion Arms CMR 9.5-inch or C4 Quad Rail 10-inch handguard, an Axelson Combat charging handle, a DLC-coated bolt carrier group and a 5.56mm NATO, QPQ-nitride-coated barrel with a 1-in-8-inch twist rate, Axelson’s A2 Blast Shield and an A2-style flash suppressor.
BCM Enhanced Lightweight Upper With KMR-A Handguard: Sure, you’ll need a tax stamp to build an SBR with BCM’s 11.5-inch-barreled Enhanced Lightweight Upper, but it’s worth the effort. This complete upper is equipped with BCM’s 10-inch KeyMod Rail-Alpha (KMR-A) handguard as well as a 5.56mm NATO barrel with a 1-in-7-inch twist rate, M4 feed ramps and a chrome-lined bore. An A2-style flash suppressor comes installed on the muzzle.
Black Rain Ordnance Left-Handed Comp3G: You left-handed shooters can stop complaining about hot gas and casings blowing back in your faces. The Left-Handed Comp3G complete 5.56mm upper receiver ejects cases on the left side of the weapon, away from a left-handed operator’s face. Made from the exact same 7075-T6 billet aluminum as Black Rain Ordnance’s standard milled upper receiver, these uppers are chambered in 5.56mm NATO and either a 16- or 18-inch, 416R stainless steel barrel with a 1-in-8-inch twist rate. Other features include a BRO SLM rail, BRO Round Competition compensator, mid-length gas system and a BRO Low Profile Adjustable Gas Block. The bolt group is nickel-boron coated and “Let It Rain” is engraved on the dust cover.
CMMG Mk4 T Upper Group: This upper from CMMG makes it easy to get into the 300 Blackout chambering. The Mk4 T Upper Group is equipped with CMMG’s free-floating, KeyMod-compatible RKM Series handguard. The upper comes with a 16.1-inch, medium-taper, 1-in-7-inch-twist barrel that is made of either 416 stainless or nitrided 4140 chrome-moly steel. An A2 compensator is threaded on the muzzle.
Dark Storm Industries DS-10 Lightning: The DS-10 Lightning is a billet-crafted upper with a forward assist, a dust cover, a Troy Alpha handguard and a free-floating, 18-inch, heavy-profile barrel chambered in .308 Winchester with a 1-in-10-inch twist rate. The upper also comes with a nickel-boron-coated bolt carrier group and a Spec Ops Gen 2 charging handle.
Dark Storm Industries DS-15 Sport: The DS-15 Sport is an economical upper made for hard use. It comes with a non-threaded barrel, but there’s no forward assist. The barrel is chambered for the 5.56mm NATO and has a 1-in-9-inch twist rate.
Del-Ton 16” Pre-Ban Heavy Flat Top Barrel Assembly: The all-business 16” Pre-Ban Heavy Flat Top Barrel Assembly from Del-Ton features a 16-inch, heavy-profile barrel chambered in 5.56 mm NATO with a 1-in-9-inch twist rate, CAR handguards with a single heat shield and A2-style flash suppressor. It also has a standard A2-style front sight post like an M16.
DPMS .308 Oracle: The .308 Oracle is a plain-Jane upper made for hard hunting or fighting. It features a 16-inch barrel made of 4140 chrome-moly steel and Glacier handguards. The gas block is also railed for the addition of a front sight.
Gemtech Integra 5.56: The Integra 5.56 from Gemtech is an integrally suppressed upper receiver that is compact and yet very easy to maintain. The Integra 5.56 uses Gemtech’s proven G-CORE suppressor technology and the Gemtech/NEMO Arms patented gas block, which eliminates blowback, making this upper receiver more comfortable to shoot.
LWRCI REPR Spiral-Fluted Upper: The REPR Spiral-Fluted Upper in 7.62mm NATO is equipped with LWRCI’s self-regulating short-stroke gas piston system. Other features include a billet aluminum receiver, a 12.5-inch modular rail, a two-position gas block and a side-mounted, non-reciprocating charging handle. The NiCorr-treated, cold-hammer-forged barrel has spiral fluting and is 20-percent lighter than a standard model. It comes with an A2-style birdcage flash suppressor and is compatible with REPR Mk I lower receivers.
POF-USA 7.62x39mm Puritan: Feeling a bit red? POF-USA offers a Puritan upper chambered for the common AK-pattern 7.62x39mm, but it’s designed to fit any mil-spec AR-15-style lower receiver. The upper features a 16.5-inch, medium-profile barrel, a gas piston operating system and a Magpul MOE handguard. Two magazines are included.
POF-USA 16.5” Black 6.8 SPC: The 16.5” Black 6.8 SPC upper from POF-USA is chambered in 6.8 SPC and features a gas piston system with a three-position gas block. The 16.5-inch, heavy-contour barrel has been fluted to reduce weight and cool down faster. The upper also comes with a nickel-plated bolt carrier group, a POF-USA MRR handguard and two magazines.
Primary Weapons Systems MK107 MOD 2: The MK107 MOD 2 upper has a 7.75-inch barrel and a gas piston system for the ultimate reliability in a super-short AR, whether it’s an SBR or pistol. The 5.56mm barrel has a 1-in-8-inch twist rate and comes capped with PWS’ CQB muzzle device.
Primary Weapons Systems MK111 MOD 1-P: The PWS MK111 MOD 1-P upper is designed for shooters wanting a compact rifle for use with a suppressor. This upper features long-strong gas piston system and an 11.85-inch barrel with a .223 Wylde chamber and a Triad 556 flash suppressor.
PSA Pistol-Length KeyMod: If a pistol build is on your agenda, the Pistol-Length KeyMod upper from PSA comes with an 8.5-inch barrel with a 5.56mm NATO chamber, a pistol-length gas system, a 7-inch 2A Armament KeyMod rail, a 0.75-inch-diameter gas block and an A2-style flash suppressor.
Seekins Precision iRMT-R MCSR: Chambered in 5.56mm NATO, the iRMT-R MCSR upper receiver from Seekins Precision is fitted with a 16-inch, match-grade barrel capped with a Seekins Melonite-finished Rook flash suppressor. The receiver is machined from a billet of 7075-T6 aluminum. The handguard mount is machined into the upper receiver to strengthen it and maintain accuracy. Finally, a Seekins 15-inch, M-LOK-compatible MCSR handguard designed for use with a sound suppressor is also added.
Stag Arms Model 3HDI Upper: This upper uses the standard direct-impingement system and is chambered in 5.56mm NATO. The 16-inch, chrome-lined, government-profile barrel is made of 4140 steel that is then given a manganese-phosphate finish. It has a 1-in-9-inch twist rate. The handguard is a drop-in Diamondhead VRS unit with a top rail that matches the upper’s and lightening cuts, and the gas block is also railed so it’s easy to add a front sight.
X Products Can Cannon: The Can Cannon allows a user to propel a soda can up to 105 yards using a proprietary gas ported barrel and pressure tube to launch heavy, thin-walled objects without burning a hole in them or directing hot gas directly into them.
YHM-7810 Specter Black Diamond: The YHM-7810 Specter Black Diamond upper from Yankee Hill Machine is available in 5.56mm NATO, 6.8 SPC or 300 Blackout. Each chambering features a 16-inch barrel, a YHM Specter-Length Diamond Handguard, a charging handle, bolt carrier group, YHM Phantom 5C2 Flash Suppressor and YHM flip-up sights.
YHM-7305 KR7 Series: Yankee Hill Machine’s KR7 series uppers are available in 5.56mm NATO, 6.8 SPC or 300 BLK, and they come standard with YHM’s Phantom 5C2 flash suppressor, a KR7 Mid-Length KeyMod handguard and a low-profile gas block. The 16-inch barrel is made of 4140 steel.
Customizing your AR for a caliber-specific scenario is as easy as pulling two pins. The modular characteristics of the AR platform make it one of the most versatile weapons systems ever designed. You can swap out the upper receiver for a specific need, like CQB and home-defense work, or change the caliber to hunt medium- to large-sized game. Complete upper receivers give you a choice—longer barrels for long-distance shooting, shorter barrels to work in close quarters. The options are endless, and life is too short to just shoot your rifle with one upper installed. Here are a few upper receivers worth considering.
