AR-15 Parts

AR-15 Parts

Shop our extensive inventory of AR-15 parts and modern sporting rifle (MSR) components. From fully assembled MIL-SPEC upper receivers and enhanced lower parts kits to free-float M-LOK handguards and ambidextrous controls, we carry the critical components required for duty, defense, and custom builds.

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  • Knight's Armament - 9 Rib Rail Panel - #97169 - 819064010838 - Boss Firearms - BossFirearms.com

    Knight's Armament - 9 Rib Rail Panel - 97169

    Knights Armament Company

    $27.99
    The Knight's Armament 9-Rib Rail Panel (KAC PN: 97169) is KAC's extended 9-rib polymer rail panel for covering unused slots on KAC RAS Picatinny quad-rail handguards. The 9-rib panel covers a larger...
    $27.99
    Qty in Cart: 0
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    $27.99
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  • LMT Defense 5.56mm 16" Piston MRP Barrel Assembly - L7PC1B - 815415011462 - Boss Firearms

    LMT Defense 5.56mm 16" Piston MRP Barrel Assembly

    LMT Defense

    $716.85
    The LMT Defense 5.56mm 16" Piston MRP Barrel Assembly (L7PC1B) is a 16-inch chrome lined 5.56×45 (.223) barrel featuring LMT's short-stroke piston operating system — the key upgrade for shooters who...
    $716.85
    Qty in Cart: 0
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    $716.85
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  • Out of stock
    On Sale
    LMT Lewis Machine & Tool DMR Buttstock - DMR - Boss Firearms

    LMT Lewis Machine & Tool DMR Buttstock

    LMT Defense

    Now: $391.50
    Was: $435.00
    LMT Lewis Machine & Tool DMR Buttstock Designated Marksman Rifle buttstock. Designed for .308 caliber rifles with carbine extension tubes. The DMR stock has comb height and length of pull adjustments...
    Now: $391.50
    Was: $435.00
    Qty in Cart: 0
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    Now: $391.50
    Was: $435.00
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  • Out of stock
    On Sale
    LMT Defense - .300 Blackout 16" Chrome Lined MRP Barrel Assembly - #L7BK1B - Boss Firearms

    LMT Defense - .300 Blackout 16" Chrome Lined MRP Barrel Assembly - #L7BK1B

    LMT Defense

    MSRP: $598.00
    Now: $538.20
    Was: $554.40
    This is a new Lewis Machine & Tool 16-inch .300 Blackout MRP barrel assembly. It features a chrome lined bore with a 1:7 right hand twist. Designed for the LMT monolithic receiver, this barrel...
    MSRP: $598.00
    Now: $538.20
    Was: $554.40
    Qty in Cart: 0
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    MSRP: $598.00
    Now: $538.20
    Was: $554.40
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  • LMT Defense - 5.56mm 16" Chrome Lined MRP Barrel Assembly - #L7PA1B - 815415010632 - Boss Firearms

    LMT Defense - 5.56mm 16" Chrome Lined MRP Barrel Assembly - L7PA1B

    LMT Defense

    MSRP: $598.00
    $554.40
    The LMT Defense 16" Chrome Lined 5.56mm MRP Barrel Assembly (L7PA1B) is engineered specifically for LMT's Monolithic Rail Platform (MRP) upper receivers. This 16-inch, 5.56×45 (.223) barrel features...
    MSRP: $598.00
    $554.40
    Qty in Cart: 0
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    MSRP: $598.00
    $554.40
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  • Out of stock
    LMT Defense - 5.56mm 10.5" Chrome Lined MRP Barrel Assembly - #L7MA1B - 815415010588 - Boss Firearms

    LMT Defense - 5.56mm 10.5" Chrome Lined MRP Barrel Assembly - L7MA1B

    LMT Defense

    $554.40
    The LMT Defense 10.5" Chrome Lined 5.56mm MRP Barrel Assembly (L7MA1B) is engineered specifically for LMT's Monolithic Rail Platform (MRP) upper receivers. This 10.5-inch, 5.56×45 (.223) barrel...
    $554.40
    Qty in Cart: 0
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    $554.40
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  • Out of stock
    On Sale
    LMT Defense - 6.8 SPC / .224 Valkyrie Enhanced AR15 Bolt - #L7Q3C - Boss Firearms

    LMT Defense - 6.8 SPC / .224 Valkyrie Enhanced AR15 Bolt - L7Q3C

    LMT Defense

    Now: $263.35
    Was: $289.00
    This is a new Lewis Machine & Tool 6.8 Special and .224 Valkyrie AR15 bolt. It features the same durable construction as LMT’s 5.56 Enhanced Bolt with an emphasis on reliability with use of...
    Now: $263.35
    Was: $289.00
    Qty in Cart: 0
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    Now: $263.35
    Was: $289.00
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  • McCollum Machine M203 37mm 12" Flare Launcher Barrel (fits Colt/LMT M203 receivers) McCollum Machine M203 37mm 12" Flare Launcher Barrel (fits Colt/LMT M203 receivers)

    McCollum Machine M203 37mm 12" Flare Launcher Barrel (fits Colt/LMT M203 receivers)

    McCollum Machine

    $529.00
    This 37mm barrel is compatible with 40mm M203 grenade launcher receivers and is intended to allow installation without requiring registration of the receiver as a Destructive Device under the NFA...
    $529.00
    Qty in Cart: 0
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    $529.00
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  • Out of stock
    McCollum Machine M203 37mm 9" Flare Launcher Barrel (fits Colt/LMT M203 receivers) McCollum Machine M203 37mm 9" Flare Launcher Barrel (fits Colt/LMT M203 receivers)

    McCollum Machine M203 37mm 9" Flare Launcher Barrel (fits Colt/LMT M203 receivers)

    McCollum Machine

    $529.00
    This 37mm barrel is compatible with 40mm M203 grenade launcher receivers and is intended to allow installation without requiring registration of the receiver as a Destructive Device under the NFA...
    $529.00
    Qty in Cart: 0
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    $529.00
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  • KAC Knights Armament Company URX 4, 5.56 M-LOK 14.5" Forend Kit 32304-1450 KAC Knights Armament Company URX 4, 5.56 M-LOK 14.5" Forend Kit 32304-1450

    KAC Knights Armament Company URX 4, 5.56 M-LOK 14.5" Forend Kit 32304-1450

    Knights Armament Company

    $373.91
    The KAC Knight's Armament URX 4, 5.56mm M-LOK 14.5" Forend Kit (KAC PN: 32304-1450) is KAC's premier free-float M-LOK handguard for AR-15/M4/SR-15 pattern rifles. The URX 4 is fully modular,...
    $373.91
    Qty in Cart: 0
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    $373.91
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  • Out of stock
    Thunder Beast - CB Series .30 Cal Non Timed Muzzle Brake 5/8x24 30CB-NTB 5/8-24

    Thunder Beast - CB Series .30 Cal Non Timed Muzzle Brake 5/8x24 30CB-NTB 5/8-24

    Thunder Beast Arms Corp

    $125.00
    The Thunder Beast Arms CB Series .30 Caliber Non-Timed Muzzle Brake with 5/8x24 threads (30CB-NTB 5/8-24) is the non-timed version of the CB muzzle brake host adapter for .30 caliber rifles. Unlike...
    $125.00
    Qty in Cart: 0
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    $125.00
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  • Out of stock
    TBAC Thunder Beast Arms Corp SR Series .338 Cal Non-Timed Muzzle Break #338SR-NTB

    TBAC Thunder Beast Arms Corp SR Series .338 Cal Non-Timed Muzzle Break #338SR-NTB

    Thunder Beast Arms Corp

    $145.00
    This is a new Thunder Beast Arms Corporation TBAC 338 SR Non-Timed Muzzle Brake. The SR mount's dual-locking system acts as a backup retention mechanism, preventing suppressor detachment under all...
    $145.00
    Qty in Cart: 0
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    $145.00
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