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Mitchell Defense The DOC AR-15 .300 BLK 10.3in Upper Receiver Chrome-Moly Barrel Black Finish M-LOK Free-Float Handguard

Mitchell Defense The DOC AR-15 .300 BLK 10.3in Upper Receiver Chrome-Moly Barrel Black Finish M-LOK Free-Float Handguard

Mitchell Defense · Upper Receiver

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Best price

$1,225.50at OpticsPlanet

In stock Sale checked Oct 13, 2026

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OpticsPlanet $1,225.50Salechecked Oct 13, 2026 In stock Buy at OpticsPlanet

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Price history

Lowest in-stock price in the last 30 days: $1,225.50 at OpticsPlanet. Dashed line = out of stock. Tracking since Oct 12, 2026.

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Since Oct 12, 2026.

About this part

The Mitchell Defense The DOC AR-15 .300 BLK 10.3in Upper Receiver Chrome-Moly Barrel Black Finish M-LOK Free-Float Handguard is a 10.3" 300 Blackout upper receiver from Mitchell Defense. One store lists it, OpticsPlanet at $1,225.50. The lowest in-stock price in the last 30 days was $1,225.50 at OpticsPlanet.

Fits and works with

Caliber
300 Blackout · Shop matching ammo
Bolt
Standard AR-15 (5.56 / 300 BLK / .350 Legend) · Bolt carrier groups
Barrel length
10.3" · Handguards

Specifications

Manufacturer
Mitchell Defense
Color
Black
Platform
AR-15
Caliber
300 Blackout

From the manufacturer

Mitchell Defense The DOC AR-15 .300 BLK 10.3in Upper Receiver Chrome-Moly Barrel Black Finish M-LOK Free-Float Handguard. 3in .300 Blackout Upper Receiver is optimized for suppressed and unsuppressed reliability with both subsonic and supersonic ammunition. The billet 7075-T6 upper includes a thermal-fit barrel seat that enhances barrel alignment and accuracy. The 10.3in barrel offers balanced rigidity and reliable ballistic performance. A standard adjustable gas block allows fine-tuning of cycling behavior to match suppressor setups or load variations. The ArmorLube Carbon Cutter BCG with Carpenter 158 HP/MPI bolt improves reliability and reduces fouling. A free-float M-LOK handguard provides versatile accessory mounting. Finished in E-Series Cerakote. Specifications for Mitchell Defense The DOC AR-15 .300 BLK 10.3in Upper Receiver: Manufacturer: Mitchell Defense Caliber: .300 AAC Blackout Overall Length: 21 in Barrel Length: 10.3 in Barrel Profile: Standard Gas System Length: Carbine Length Barrel Twist Rate: 1-7 Firearms Threads Per Inch: Non Threaded Muzzle Device: A2 Flash Hider Finish: Nitride Gun Model: AR-15 Fabric/Material: 4150 CrMoV Gun Make: AR Platform Bolt Carrier Group Included: MIL-SPEC Charging Handle Included: MIL-SPEC Country of Origin: USA Features of Mitchell Defense The DOC AR-15 .300 BLK 10.3in Upper Receiver Adjustable gas block enables precise tuning for ammunition and suppressors Thermal-fit billet upper enhances stability and accuracy ArmorLube Carbon Cutter BCG with C158 HP/MPI bolt ensures dependable cycling M-LOK handguard provides lightweight modularity Package Contents: Mitchell Defense The DOC AR-15 .300 BLK 10.3in Upper Receiver What firearm models does the manufacturer say Mitchell Defense The DOC AR-15 .300 BLK 10.3in Upper Receiver is compatible with? The manufacturer says that Mitchell Defense The DOC AR-15 .300 BLK 10.3in Upper Receiver is compatible with AR-15Mitchell Defense 421121: The DOC AR-15 .300 BLK 10.3in Upper Receiver Chrome-Moly Barrel Black Finish M-LOK Free-Float Handguard

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$1,225.50 at OpticsPlanet
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