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"PLUG-N-PLAY" GAS PISTON CONVERION!

Brownells BRN-4 Upper Receiver

Built with all new-manufactured HK416-compatible parts. Drops onto any standard "mil-spec" AR-15 lower!

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Rifle Parts

2026 Items

Browse Rifle Parts Products Up To 83% Off including Rifle Receivers & Parts, Rifle Stocks & Parts, & Rifle Sights & Parts! - 4,673 Products / 329 Brands

Take a look at 4,673 Rifle Parts Products Up To 83% Off within our Gun Parts including Rifle Receivers & Parts, Rifle Stocks & Parts, & Rifle Sights & Parts From Top Brands like BROWNELLS, AERO PRECISION, CMMG and more!

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Product badge CMMG - AR-15/M16 22LR BRAVO CONVERSION KITS CMMG - AR-15/M16 22LR BRAVO CONVERSION KITS
5 Stars
(4.5)

$164.99 - $195.99

$189.99

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Product badge LAW TACTICAL LLC - AR-15/M16 GEN3-M FOLDING STOCK ADAPTER LAW TACTICAL LLC - AR-15/M16 GEN3-M FOLDING STOCK ADAPTER
5 Stars
(4.6)

$239.99

$269.99 - $279.99

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Product badge GEISSELE AUTOMATICS LLC - AR-15 ENHANCED TRIGGERS GEISSELE AUTOMATICS LLC - AR-15 ENHANCED TRIGGERS
5 Stars
(4.4)

$159.99

$189.99

In stock
Product badge MAGPUL - AR-15/M16 B.A.D. LEVER™ MAGPUL - AR-15/M16 B.A.D. LEVER™
5 Stars
(4.4)

$26.99

$31.30

In stock
GEISSELE AUTOMATICS LLC - AR-15/M16/308 AR SSA & SSA-E TRIGGER GEISSELE AUTOMATICS LLC - AR-15/M16/308 AR SSA & SSA-E TRIGGER
5 Stars
(4.9)
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J P ENTERPRISES - AR-15 REDUCED POWER SPRING KIT J P ENTERPRISES - AR-15 REDUCED POWER SPRING KIT
5 Stars
(4.6)

$10.40

In stock
ALG DEFENSE - AR-15 ENHANCED MILITARY-STYLE TRIGGERS ALG DEFENSE - AR-15 ENHANCED MILITARY-STYLE TRIGGERS
5 Stars
(4.6)

$68.25 - $79.00

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Product badge BROWNELLS - M16 5.56 LIGHTWEIGHT BOLT CARRIER GROUP BROWNELLS - M16 5.56 LIGHTWEIGHT BOLT CARRIER GROUP
5 Stars
(4.5)

$79.99 - $109.99

$149.99 - $239.99

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Product badge CMC TRIGGERS - AR-15 TACTICAL TRIGGER GROUP CMC TRIGGERS - AR-15 TACTICAL TRIGGER GROUP
5 Stars
(4.5)

$129.99 - $174.00

$139.99

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Product badge LUTH-AR LLC - AR-15 A1 REAR SIGHT ASSEMBLY LUTH-AR LLC - AR-15 A1 REAR SIGHT ASSEMBLY
5 Stars
(2.9)
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Product badge AERO PRECISION - AR-15 M4E1 STRIPPED LOWER RECEIVERS 5.56MM AERO PRECISION - AR-15 M4E1 STRIPPED LOWER RECEIVERS 5.56MM
5 Stars
(4.7)

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ROCK RIVER ARMS - AR-15 NATIONAL MATCH 2-STAGE TRIGGER ROCK RIVER ARMS - AR-15 NATIONAL MATCH 2-STAGE TRIGGER
5 Stars
(4.0)

$106.99

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Product badge WHITE OAK ARMAMENT - AR-15/M16 223 WYLDE MATCH BARRELS WHITE OAK ARMAMENT - AR-15/M16 223 WYLDE MATCH BARRELS
5 Stars
(4.5)

$279.99 - $289.99

$288.99 - $295.49

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TIMNEY - AR-15 DROP-IN TRIGGER MODULE SOLID SHOE TIMNEY - AR-15 DROP-IN TRIGGER MODULE SOLID SHOE
5 Stars
(4.5)
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GEISSELE AUTOMATICS LLC - SUPER DYNAMIC TRIGGERS FOR AR-15 GEISSELE AUTOMATICS LLC - SUPER DYNAMIC TRIGGERS FOR AR-15
5 Stars
(4.9)
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Product badge KE ARMS LLC - AR-15 KP-15 STRIPPED LOWER RECEIVERS POLYMER KE ARMS LLC - AR-15 KP-15 STRIPPED LOWER RECEIVERS POLYMER
5 Stars
(4.5)

$69.99

$109.99

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Product badge MAGPUL - AR-15 MBUS GEN 2 SIGHT SET MAGPUL - AR-15 MBUS GEN 2 SIGHT SET
5 Stars
(4.5)

$64.99

$68.99

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Product badge FOXTROT MIKE PRODUCTS - AR-15 9MM UPPER RECEIVERS M-LOK ASSEMBLED FOXTROT MIKE PRODUCTS - AR-15 9MM UPPER RECEIVERS M-LOK ASSEMBLED
5 Stars
(4.9)

$259.99 - $399.99

$379.99 - $429.99

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AERO PRECISION - AR-15 GEN 2 STRIPPED LOWER RECEIVER AERO PRECISION - AR-15 GEN 2 STRIPPED LOWER RECEIVER
5 Stars
(4.5)

$110.49 - $114.99

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Product badge MAGPUL - AR-15 CTR STOCK COLLAPSIBLE MIL-SPEC MAGPUL - AR-15 CTR STOCK COLLAPSIBLE MIL-SPEC
5 Stars
(4.8)

$46.99 - $52.99

$61.70

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YANKEE HILL MACHINE CO., INC. - AR-15/M16 EZ PULL PIVOT & TAKEDOWN PIN SET YANKEE HILL MACHINE CO., INC. - AR-15/M16 EZ PULL PIVOT & TAKEDOWN PIN SET
5 Stars
(4.2)

$17.40

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BROWNELLS BUNDLES - M16 5.56 BOLT CARRIER GROUP NITRIDE MP BROWNELLS BUNDLES - M16 5.56 BOLT CARRIER GROUP NITRIDE MP
5 Stars
(4.5)

$109.99

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CRITERION BARRELS INC - AR-15/M16 223 WYLDE CHROME LINED BARRELS CRITERION BARRELS INC - AR-15/M16 223 WYLDE CHROME LINED BARRELS
5 Stars
(4.9)

$269.99 - $296.99

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HOGUE - AR-15 PISTOL GRIP HOGUE - AR-15 PISTOL GRIP
5 Stars
(4.8)

$25.46

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