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"Innovative firearm accessories engineered for performance"

SI designs rugged, user-focused firearm components and optics. They make accessories like slide plates, charging handles, barrel clamps, red dots, and shotgun parts.

5.0★★★★★(82 verified SI reviews)

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7,593

Products

2,402

In Stock

Founded

USA

Origin

All SI Products (2,402)

Sinclair INTERNATIONAL PRIMING HEAD TOOL PPC

Sinclair INTERNATIONAL PRIMING HEAD TOOL 223 FAMILY

Sinclair INTERNATIONAL SHOOTING REST SPEED SCREW 1/2"X20 THREADS

Sinclair INTERNATIONAL STUCK CASE REMOVER

Sinclair INTERNATIONAL CASE PREP CENTER ADAPTER

Sinclair INTERNATIONAL BRASS CASE BRITE MEDIA STAINLESS STEEL 5 POUNDS

Sinclair INTERNATIONAL TRIMMER STAND ONLY

Sinclair INTERNATIONAL PILOT STOP STAINLESS STEEL 50 CALIBER

Sinclair INTERNATIONAL NECK TURNING MANDREL SS 8MM (.321")

Sinclair INTERNATIONAL CROSS BOLT DIE LOCKING RING STAINLESS STEEL 3 PACK

Sinclair INTERNATIONAL DIE LOCK RING PLIERS FOR SINCLAIR

Sinclair INTERNATIONAL UNIVERSAL FLASH HOLE DEBURRING TOOL GEN 2 HANDLE

Sinclair INTERNATIONAL ALL-PURPOSE SHOOTING REST NON-WINDAGE REST TOP

Sinclair INTERNATIONAL STAINLESS STEEL EXPANDER MANDREL 8MM (.322")

Sinclair INTERNATIONAL NECK TURNING CASE HOLDER #8 505 GIBBS

SINCLAIR INTERNATIONAL BULLET SORTING STAND WITHOUT INDICATOR

Sinclair INTERNATIONAL BENCHREST SHOOTING REST FOREND RAIL ADAPTER

Sinclair INTERNATIONAL PRIMING TOOL KIT CASE

Sinclair INTERNATIONAL PRIMER POCKET UNIFORMER KIT - CASE ONLY

Sinclair INTERNATIONAL NECK TURNING FEELER GAGE SET

Sinclair INTERNATIONAL LINEAR BUBBLE LEVEL

Sinclair INTERNATIONAL NECK TURNING TOOL LARGE .35-.50 CALIBER NT-5000

Sinclair INTERNATIONAL ALL-PURPOSE SHOOTING REST RIGHT HAND WINDAGE TOP

Sinclair INTERNATIONAL FLASH HOLE DEBURR KIT CASE

Sinclair INTERNATIONAL DIAL INDICATOR WITH LEVER

Sinclair INTERNATIONAL COMPARATOR/BUMP GAGE KIT CASE ONLY

Sinclair INTERNATIONAL ALL-PURPOSE SHOOTING REST CLAMP LEVER UPGRADE KIT

Sinclair INTERNATIONAL BULLET COMPARATOR 6MM (0.243")

Sinclair INTERNATIONAL BULLET COMPARATOR 30 CALIBER (0.308")

Sinclair INTERNATIONAL BULLET SEATING DEPTH GUIDE AR-308

Sinclair INTERNATIONAL PILOT STOP STAINLESS STEEL 9.3MM

Sinclair International Priming Head Tool 505 Gibbs

Sinclair INTERNATIONAL PRIMING HEAD TOOL 338 LAPUA

Sinclair INTERNATIONAL LARGER CALIBER EXPANDER DIE BODY 35-50 CALIBER

Sinclair INTERNATIONAL FLASH HOLE REAMER 0.081"

Sinclair International All-Purpose Lightweight Shooting Rest

Sinclair INTERNATIONAL CONCENTRICITY GAUGE WITH DIGITAL INDICATOR

Sinclair International Adjustable Shooting Stool Foldable 110BK

SINCLAIR INTERNATIONAL CONCENTRICITY GAUGE WITHOUT DIGITAL INDICATOR

Sinclair INTERNATIONAL CASE NECK SORTING TOOL WITH DIAL INDICATOR

Sinclair INTERNATIONAL WOODEN PRESS STAND

Sinclair INTERNATIONAL PREMIUM SCOPE ALIGNMENT TOOL

Sinclair International Case Neck Sorting Tool Reloading

Sinclair INTERNATIONAL PRIMER POCKET UNIFORMER KIT WITH HANDLE CARBIDE

Sinclair INTERNATIONAL CARBIDE NECK TURNING MANDREL 22 CALIBER (.222")

Sinclair INTERNATIONAL CARBIDE NECK TURNING MANDREL 338 CALIBER (.336")

Sinclair INTERNATIONAL CARBIDE NECK TURNING MANDREL 7MM (.282")

Sinclair INTERNATIONAL CARBIDE NECK TURNING MANDREL 25 CALIBER (.255")

About SI

SI focuses on practical, performance-driven firearm accessories for a wide range of pistols, rifles, and shotguns. Their lineup includes slide adapter plates, latchless charging handles, barrel clamps, compact red dot optics, and dedicated shotgun components, built primarily from aluminum and hardened materials. Products are engineered with attention to fit, function, and ease of installation, aimed at shooters who want reliable upgrades without unnecessary complexity. SI supports competitive, tactical, and recreational shooters by offering parts that address common user needs and enhance firearm ergonomics and capability.

Headquarters

Established

Country of Origin

USA

History & Heritage

SI began as an American aftermarket parts maker aimed at providing functional, affordable upgrades and accessories for shooters. Over time the brand expanded its offerings across pistol, rifle, and shotgun platforms, becoming known for practical designs and broad compatibility.