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300 Blackout Upper Receivers | 300 AAC BLK Uppers from Top Brands like Aero Precision, Radical Firearms & More — 231 products / 761 models

The future of the AR 15 is the 300 Blackout. The key to making your AR 15 compatible with 300 Blackout ammo is your AR 15 upper, and when making your AR-15 or M4 compatible with 300 BLK ammo, you want the best 300 Blackout upper receiver for your dollar. Luckily, we carry one of the biggest supplies of 300 BLK uppers at some of the best prices on the market. Our collection of 300 Blackout ACC uppers include Aero Precision uppers, Radical Firearms uppers, Ghost uppers, and tons of other AR upper receivers from the brands you know and love.image

Don't stop with just the AR-15 upper receiver though. We also sell a huge array of other 300 Blackout accessories and gear that will increase your range, accuracy, and control, including : 300 Blackout rifle scopes, 300 Blackout muzzle devices, 300 Blackout reloading equipment, and 300 Blackout barrels. Buy a 300 BLK upper receiver today, and make sure to check out all of our AR 15 parts to shop for high-quality gear for your other ARs.

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Image of Daniel Defense DDM4 300 S, URG, 10.3in, 300 AAC Blackout Complete Upper Receiver w/ Flash Hider 2 models Daniel Defense DDM4 300 S, URG, 10.3in, 300 AAC Blackout Complete Upper Receiver w/ Flash Hider (16) As Low As (Save Up to 24%) $1,109.00 12% Coupon
Image of Sons of Liberty Gun Works M4-89 .300 AAC Blackout Half Complete Upper Receiver Sons of Liberty Gun Works M4-89 .300 AAC Blackout Half Complete Upper Receiver List: $1,000.00 (Save $50.00) $950.00
Image of Jacob Grey Firearms Ultralight 300 BO Complete Upper Assembly 4 models Jacob Grey Firearms Ultralight 300 BO Complete Upper Assembly (6) As Low As (Save Up to 54%) $399.00 Blazin' Deal
Image of TRYBE Defense AR-15 Magnite 16in M-LOK Complete Upper Receiver, 5.56x45mm NATO, Version 2 TRYBE Defense AR-15 Magnite 16in M-LOK Complete Upper Receiver, 5.56x45mm NATO, Version 2 (1) List: $849.99 (Save 29%) $599.99 Free Gift Available
Image of V Seven 300 Blackout LR Enlightened Complete Upper V Seven 300 Blackout LR Enlightened Complete Upper List: $1,970.00 (Save $59.10) $1,910.90
Image of POF USA P415 Edge 10.5 in Barrel 5.56x45mm NATO Upper Receiver Assembly 4 models POF USA P415 Edge 10.5 in Barrel 5.56x45mm NATO Upper Receiver Assembly (3) As Low As (Save Up to $111.00) $1,359.00
Image of Aero Precision M4E1-T 8in .300 AAC Blackout Complete Upper Receiver with Flash Hider made-in-usa-flag 2 models Aero Precision M4E1-T 8in .300 AAC Blackout Complete Upper Receiver with Flash Hider (1) As Low As (Save Up to 10%) $419.99 Free 2 Day Shipping
Image of Aero Precision M4E1 Threaded 8in .300 Blackout Complete Upper Receiver with Flash Hider made-in-usa-flag 4 models Aero Precision M4E1 Threaded 8in .300 Blackout Complete Upper Receiver with Flash Hider (19) As Low As (Save 10%) $534.99 Best Rated
Image of TRYBE Defense Magnite AR-15 .300 BLK 16in Complete Upper Receiver TRYBE Defense Magnite AR-15 .300 BLK 16in Complete Upper Receiver List: $849.99 (Save 29%) $599.99 Free 2 Day Shipping
Image of CMMG DISSENT Mk4, 300BLK, 6.5in Upper Receiver 7 models CMMG DISSENT Mk4, 300BLK, 6.5in Upper Receiver (3) As Low As (Save Up to 11%) $1,099.00
Image of Aero Precision M4E1 16in .300 Blackout Barrel Complete Upper Receiver with Flash Hider made-in-usa-flag 8 models Aero Precision M4E1 16in .300 Blackout Barrel Complete Upper Receiver with Flash Hider (12) As Low As (Save Up to 20%) $441.99 Best Rated
Image of TRYBE Defense AR-15 Magnite 10.5in M-LOK Complete Upper Receiver, Enhanced BCG, .223 Wylde, Version 2 TRYBE Defense AR-15 Magnite 10.5in M-LOK Complete Upper Receiver, Enhanced BCG, .223 Wylde, Version 2 List: $899.99 (Save 30%) $629.99 Free Gift Available
Image of Aero Precision M4E1 Threaded 16in .300 Blackout w/ ATLAS S-ONE Handguard Complete Upper Receiver with Flash Hider made-in-usa-flag 5 models Aero Precision M4E1 Threaded 16in .300 Blackout w/ ATLAS S-ONE Handguard Complete Upper Receiver with Flash Hider (9) As Low As (Save 10%) $494.99 Best Rated
Image of TRYBE Defense AR-15 Magnite 10.5in M-LOK Complete Upper Receiver, .300 BLK, Version 2 TRYBE Defense AR-15 Magnite 10.5in M-LOK Complete Upper Receiver, .300 BLK, Version 2 (2) List: $849.99 (Save 29%) $599.99 Free 2 Day Shipping
Image of TRYBE Defense AR-15 Magnite 16in M-LOK Complete Upper Receiver, .223 Wylde, Version 2 TRYBE Defense AR-15 Magnite 16in M-LOK Complete Upper Receiver, .223 Wylde, Version 2 List: $849.99 (Save 29%) $599.99 Free Gift Available
Image of Aero Precision M4E1 Threaded 10in .300 Blackout Complete Upper Receiver with Flash Hider made-in-usa-flag 4 models Aero Precision M4E1 Threaded 10in .300 Blackout Complete Upper Receiver with Flash Hider (24) As Low As (Save 10%) $554.99 Best Rated
Image of Moriarti AR-15 10.5 inch .300 Blackout Upper Receiver Stripped Moriarti AR-15 10.5 inch .300 Blackout Upper Receiver Stripped List: $399.95 (Save 17%) $333.63 Blazin' Deal
Image of Aero Precision M4E1-T 10in .300 AAC Blackout Complete Upper Receiver made-in-usa-flag 4 models Aero Precision M4E1-T 10in .300 AAC Blackout Complete Upper Receiver (1) As Low As (Save Up to 18%) $393.99 Free 2 Day Shipping
Image of Dark Storm Industries DS-15 MOE Model Complete .300 Blackout Non-Threaded Upper Receiver Dark Storm Industries DS-15 MOE Model Complete .300 Blackout Non-Threaded Upper Receiver (1) List: $679.00 (Save 12%) $599.95
Image of CMMG DISSENT Mk4, 300BLK, 10.5in Upper Receiver 8 models CMMG DISSENT Mk4, 300BLK, 10.5in Upper Receiver (1) As Low As (Save Up to 16%) $1,069.00
Image of POF USA Complete P-415 Edge 16.5 in Barrel 5.56x45mm NATO Upper Receiver 4 models POF USA Complete P-415 Edge 16.5 in Barrel 5.56x45mm NATO Upper Receiver (6) As Low As (Save Up to 10%) $1,359.00 Blazin' Deal
Image of OpticsPlanet Exclusive Moriarti AR-15 10.5in 300 Blackout Upper Receiver, A2 Flash Hider OpticsPlanet Exclusive Moriarti AR-15 10.5in 300 Blackout Upper Receiver, A2 Flash Hider (6) List: $379.95 (Save 18%) $311.79 Blazin' Deal
Image of Spikes Tactical 300 Black Out 16in Forged Upper Receiver made-in-usa-flag Spikes Tactical 300 Black Out 16in Forged Upper Receiver (3) List: $770.00 (Save 10%) $693.00
Image of Aero Precision M4E1-T 16in .300 AAC Blackout RM15 Complete Upper Receiver made-in-usa-flag Aero Precision M4E1-T 16in .300 AAC Blackout RM15 Complete Upper Receiver List: $595.00 (Save 10%) $534.99
Image of OpticsPlanet Exclusive Moriarti AR-15 10.5in 300 Blackout Upper Receiver, Slanted Muzzle OpticsPlanet Exclusive Moriarti AR-15 10.5in 300 Blackout Upper Receiver, Slanted Muzzle List: $399.95 (Save 23%) $306.84 Blazin' Deal
Image of Aero Precision M4E1 10in .300 Barrel Complete Upper with Flash Hider made-in-usa-flag 4 models Aero Precision M4E1 10in .300 Barrel Complete Upper with Flash Hider (9) As Low As (Save 10%) $474.99 Best Rated
Image of Dark Storm Industries DS-15 Typhoon 7.5in .300 Blackout Complete Upper Receiver Dark Storm Industries DS-15 Typhoon 7.5in .300 Blackout Complete Upper Receiver List: $919.00 (Save 13%) $799.95
Image of CMMG Mk4 .300BLK 12.5in Banshee Upper Group Receiver 6 models CMMG Mk4 .300BLK 12.5in Banshee Upper Group Receiver As Low As (Save Up to 19%) $710.49 Blazin' Deal
Image of Ghost Firearms Upper Receiver, Pistol Lower Parts Kit, .300 Blackout, 10.5in Pistol, Moly Steel Barrel, 1-8 Twist, M-LOK Free Float Hand Guard 23 models Ghost Firearms Upper Receiver, Pistol Lower Parts Kit, .300 Blackout, 10.5in Pistol, Moly Steel Barrel, 1-8 Twist, M-LOK Free Float Hand Guard (5) As Low As (Save Up to 22%) $449.99
Image of Moriarti AR-15 300 Blackout 16in Diamond Cut 12in MLok Upper Assembly Moriarti AR-15 300 Blackout 16in Diamond Cut 12in MLok Upper Assembly List: $399.95 (Save 15%) $339.99 Free 2 Day Shipping
Image of Moriarti AR-15 10 inch .300 Blackout Upper Receiver with Flash Hider Assembly Moriarti AR-15 10 inch .300 Blackout Upper Receiver with Flash Hider Assembly List: $399.95 (Save 26%) $297.82 Blazin' Deal
Image of Geissele Super Duty Mod1 8in Upper Receiver Group 2 models Geissele Super Duty Mod1 8in Upper Receiver Group As Low As (Save Up to $43.80) $1,285.20
Image of Primary Weapons Systems MK109 MOD1-M 9.75-inch Upper Receiver Primary Weapons Systems MK109 MOD1-M 9.75-inch Upper Receiver (1) List: $1,129.95 (Save $80.00) $1,049.95
Image of OpticsPlanet Exclusive Moriarti AR-15 10.5in 300 Blackout Upper Receiver, Triport OpticsPlanet Exclusive Moriarti AR-15 10.5in 300 Blackout Upper Receiver, Triport (1) List: $369.95 (Save 17%) $307.52 Blazin' Deal
Image of Ghost Firearms Elite 10.5 in .300 Blackout Complete Upper Receiver with Flash Hider 6 models Ghost Firearms Elite 10.5 in .300 Blackout Complete Upper Receiver with Flash Hider (7) As Low As (Save Up to 20%) $263.99 Free 2 Day Shipping
Image of Aero Precision M4E1 8in .300 CMV Barrel Complete Upper Assembly with Flash Hider made-in-usa-flag 3 models Aero Precision M4E1 8in .300 CMV Barrel Complete Upper Assembly with Flash Hider (22) As Low As (Save 10%) $489.99 Best Rated
Image of Primary Weapons Systems MK109 MOD 2-M, .300 AAC Blackout, 9.75 inch Upper Receiver Primary Weapons Systems MK109 MOD 2-M, .300 AAC Blackout, 9.75 inch Upper Receiver (1) List: $1,399.95 (Save $100.00) $1,299.95
Image of Bear Creek Arsenal BC-15 .300 Blackout 7.5in Bolt Action Style Upper Receiver Bear Creek Arsenal BC-15 .300 Blackout 7.5in Bolt Action Style Upper Receiver List: $299.95 (Save $9.96) $289.99
Image of Ghost Firearms Elite 7.5 in .300 Blackout Complete Upper Receiver with Flash Hider 6 models Ghost Firearms Elite 7.5 in .300 Blackout Complete Upper Receiver with Flash Hider As Low As (Save Up to 20%) $263.99
Image of Dark Storm Industries DS-15, AR-15, .300 AAC Blackout, 16 inch, Upper Receiver 2 models Dark Storm Industries DS-15, AR-15, .300 AAC Blackout, 16 inch, Upper Receiver As Low As (Save Up to 12%) $559.99
Image of ABC RIFLE COMPANY AR-15 .300 AAC Blackout Pistol M-LOK Handguard Complete Upper Receiver w/BCG And Charging Handle 5 models ABC RIFLE COMPANY AR-15 .300 AAC Blackout Pistol M-LOK Handguard Complete Upper Receiver w/BCG And Charging Handle As Low As (Save Up to 50%) $299.99 Free 2 Day Shipping
Image of Bear Creek Arsenal BC-15 .300 Blackout 8.5in Bolt Action Style Upper Receiver Bear Creek Arsenal BC-15 .300 Blackout 8.5in Bolt Action Style Upper Receiver List: $299.95 (Save 13%) $259.99
Image of Grid Defense .300 Blackout Upper Receiver 15 models Grid Defense .300 Blackout Upper Receiver (7) As Low As (Save Up to 41%) $222.49 Blazin' Deal
Image of Sharps Bros. AR-15 Billet Stripped Upper Receiver w/Forward Assist Sharps Bros. AR-15 Billet Stripped Upper Receiver w/Forward Assist (3) List: $204.95 (Save 10%) $184.97 Free 2 Day Shipping
Image of ABC RIFLE COMPANY AR-15 .300 AAC Blackout Micro Pistol 5in Barrel M-LOK Handguard Upper Receiver w/BCG And Charging Handle 9 models ABC RIFLE COMPANY AR-15 .300 AAC Blackout Micro Pistol 5in Barrel M-LOK Handguard Upper Receiver w/BCG And Charging Handle As Low As (Save Up to 40%) $299.99 On Sale
Image of OpticsPlanet Exclusive Moriarti AR-15 16in 300 Blackout Upper Receiver, Triport OpticsPlanet Exclusive Moriarti AR-15 16in 300 Blackout Upper Receiver, Triport List: $369.95 (Save $29.96) $339.99
Image of Ghost Firearms Vital .300 Blackout Upper Receiver 3 models Ghost Firearms Vital .300 Blackout Upper Receiver (9) As Low As (Save Up to 13%) $259.99
Image of Bear Creek Arsenal BC-15 .300 Blackout 16in Upper Receiver 9 models Bear Creek Arsenal BC-15 .300 Blackout 16in Upper Receiver As Low As (Save Up to 20%) $293.99
Image of CMMG Upper Group Resolute Mk4 .300 AAC 14.5in P&W Upper Receiver CMMG Upper Group Resolute Mk4 .300 AAC 14.5in P&W Upper Receiver List: $559.95 (Save 12%) $489.99
Image of JARD AR Side Charge .223/5.56 Upper Receiver Assembly 3 models JARD AR Side Charge .223/5.56 Upper Receiver Assembly (1) As Low As (Save Up to 18%) $329.95 Final Sale
Image of TacFire .300 Blackout Complete M-LOK Upper Assembly made-in-usa-flag 3 models TacFire .300 Blackout Complete M-LOK Upper Assembly (1) As Low As (Save Up to 21%) $289.99
Image of Bear Creek Arsenal BC-15 .300 Blackout 16in Bolt Action Style Upper Receiver 3 models Bear Creek Arsenal BC-15 .300 Blackout 16in Bolt Action Style Upper Receiver As Low As (Save Up to 14%) $279.99
Image of Ghost Firearms Elite 16 in .300 Blackout Complete Upper Receiver with Flash Hider 3 models Ghost Firearms Elite 16 in .300 Blackout Complete Upper Receiver with Flash Hider (22) As Low As (Save Up to 20%) $279.99 Best Rated
Image of Bear Creek Arsenal BC-15 .300 Blackout 10.5in Bolt Action Style Upper Receiver Bear Creek Arsenal BC-15 .300 Blackout 10.5in Bolt Action Style Upper Receiver List: $299.95 (Save 12%) $263.99
Image of Troy 12.5in 300AAC Caliber SOCC Rail Handguard A4 Upper Receiver Kit w/Sights made-in-usa-flag Troy 12.5in 300AAC Caliber SOCC Rail Handguard A4 Upper Receiver Kit w/Sights List: $940.00 (Save 17%) $779.99
Image of Rock River Arms Coyote Carbine .300 AAC Blackout Completed Upper Rock River Arms Coyote Carbine .300 AAC Blackout Completed Upper List: $715.00 (Save 10%) $639.99
Image of AT3 Tactical Tactical AR-15 Slick Side Billet Upper Receiver 7 models AT3 Tactical Tactical AR-15 Slick Side Billet Upper Receiver (2) As Low As (Save 30%) $89.99 10% Coupon
Image of CMMG Mk4 .300BLK 8in Banshee Upper Group Receiver 11 models CMMG Mk4 .300BLK 8in Banshee Upper Group Receiver As Low As (Save Up to 10%) $789.99
Image of ABC RIFLE COMPANY AR-15 .300 AAC Blackout Complete Build 16in Barrel 15in Lightweight Hybrid M-LOK Handguard Upper Receiver 5 models ABC RIFLE COMPANY AR-15 .300 AAC Blackout Complete Build 16in Barrel 15in Lightweight Hybrid M-LOK Handguard Upper Receiver As Low As (Save Up to 11%) $355.99
Image of ABC RIFLE COMPANY AR-15 .300 AAC Blackout Micro Pistol 5in Barrel Custom 5in Top Cut Custom M-LOK Handguard Complete Upper Receiver w/BCG And Charging Handle 8 models ABC RIFLE COMPANY AR-15 .300 AAC Blackout Micro Pistol 5in Barrel Custom 5in Top Cut Custom M-LOK Handguard Complete Upper Receiver w/BCG And Charging Handle As Low As (Save Up to 23%) $299.99
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