CMMG

CMMG AR-15 HD Pivot and Takedown Pin Parts Kit - 55AFF3B

CMMG AR-15 HD Pivot and Takedown Pin Parts Kit - 55AFF3B - Takedown Pin for AR-15 - view 1
CMMG AR-15 HD Pivot and Takedown Pin Parts Kit - 55AFF3B - Takedown Pin for AR-15 - view 2
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Overview

The CMMG AR-15 HD Pivot and Takedown Pin Parts Kit is designed to provide a reliable and sturdy solution for securing your AR-15 upper and lower receivers. Made from steel, this pin set is essential for maintaining the structural integrity of your firearm during assembly and disassembly. This kit is frequently found in builds utilizing a mid-length gas system chambered in 5.56 NATO, making it a solid choice for those configurations.

Specifications

MPN55AFF3B
Pin TypePin Set
MaterialSteel

Available Merchants(11)

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Frequently Built With

Based on build data

Build Configuration Breakdown

Aggregated and anonymized data showing how builders use this product

Platform

72.6%
AR-1572.6%
AR-1023%
AR-94.4%

Caliber

64.8%
5.56 NATO64.8%
.223 Wylde15.5%
300 Blackout5.6%
6mm ARC4.2%
9mm2.8%
Other7%

Gas System

52.6%
Mid-Length52.6%
Carbine24.6%
Rifle12.3%
Pistol8.8%
Intermediate1.8%
Frequently Built With Products
ProductCategoryTimes Built Together
Strike Industries Extended Bolt Catch316
B5 Systems Trigger Guard ATG-001-01287
Bravo Company Ar-15/m16 Bcm Mil-Spec 6 Position Receiver Extension269
Timber Creek Outdoors Ambidextrous Safety Selector - Black248
Strike Industries Ambidextrous Magazine Release, Black - ARAMBIMRBK186
Geissele Automatics Llc Ar-15 Ssa-E X Lightning Bow Trigger181
Build Platform Breakdown
PlatformPercentage
AR-1572.6%
AR-1023%
AR-94.4%
Build Caliber Breakdown
CaliberPercentage
5.56 NATO64.8%
.223 Wylde15.5%
300 Blackout5.6%
6mm ARC4.2%
9mm2.8%
.223 Remington1.4%
.224 Valkyrie1.4%
.308 Win1.4%
.450 Bushmaster1.4%
6.5 Grendel1.4%
Build Gas System Breakdown
Gas SystemPercentage
Mid-Length52.6%
Carbine24.6%
Rifle12.3%
Pistol8.8%
Intermediate1.8%

Builds Featuring This Part

See all 171

Builds in the community that include the CMMG AR-15 HD Pivot and Takedown Pin Parts Kit - 55AFF3B

BuildPartsTotal
Truck gun 16"
22$866.07
Aero precision 16" 5.56
22$1430.70
my 5.56 build
21$730.68
My 5.56 build
23$3697.33
16" 5.56
22$855.80
PDW 16" 5.56
18$1148.69
aero precision 20" build
17$2538.59
for nothing in particular 16"
17$730.70
Second 5.56 build
22$2083.28
new 5.56 build
17$780.28
16" build
28$3571.20
new 5.56 build
27$1868.92

Customer reviews

4.9out of 5

8 global ratings

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Top reviews

R
razey
CMMG HD pin kit complete
Reviewed on May 14, 2026Verified with Build

CMMG HD pin kit is the full assembly with springs, detents, and the upgraded pin heads. The HD profile is heavier than milspec but the takedown feels positive. Phosphate finish across steel parts. Easier than piecing together a milspec pin set from different sources.

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B
BIGBLUEDODGE1997
CMMG HD pins
Reviewed on May 3, 2026Verified with Build

heavy duty pivot and takedown pin kit, the pins are slightly larger diameter than mil spec which removes any rock between upper and lower. install was direct after a light chamfer pass with a reamer. premium upgrade for builds with sloppy pin holes

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F
FurrCh0pz
CMMG HD pin kit matches
Reviewed on April 9, 2026Verified with Build

CMMG HD pin kit anodize matches my CMMG receiver well. HD profile is heavier than mil-spec but the takedown feels positive. Spring tensions are correct on the supplied detents. Phosphate finish on the steel parts is consistent.

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F
Figtree76
Complete kit ready to assemble
Reviewed on March 30, 2026Verified with Build

CMMGs HD pin kit includes the pins, springs, detents, and the small parts needed for a complete lower build. The HD pins themselves have a slightly larger head profile which makes takedown easier. Phosphate finish across all the steel parts. Saves piecing things together.

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B
BCE
minor gripes
Reviewed on March 12, 2026Verified with Build

good upgrade but the finish has a slight color variation from the other parts in my build

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O
orkaydk98
HD pin upgrade
Reviewed on March 9, 2026Verified with Build

CMMG heavy duty pin set fixes loose pin holes on cheaper lowers. slightly oversize fit means no rock between halves. detent engagement is positive. one of the best small upgrades for any sloppy build

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C
clarkclint10104
HD pins complete kit
Reviewed on February 20, 2026Verified with Build

CMMG includes the springs and detents along with the pins which is convenient. HD profile is heavier than standard but the takedown action feels positive. Phosphate finish on the steel parts is consistent. Easy install on an unbuilt lower. Saves time vs sourcing parts individually.

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S
SleazyGoyim
CMMG HD pin kit drops in
Reviewed on January 26, 2026Verified with Build

CMMG HD pin kit drops into a milspec lower with the included springs and detents. HD profile heads are easier to grip than standard mil spec. Phosphate finish on the steel parts. Saves piecing together small parts individually.

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