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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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7,545

Products

2,386

In Stock

Founded

USA

Origin

All SI Products (2,386)

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 (7/8"-14)

Sinclair INTERNATIONAL FLASH HOLE REAMER 0.081"

Sinclair INTERNATIONAL CONCENTRICITY GAUGE WITH DIGITAL INDICATOR

Sinclair INTERNATIONAL ADJUSTABLE SHOOTING STOOL

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")

Sinclair INTERNATIONAL SCOPE RING LAPPING TOOL 30MM

Sinclair INTERNATIONAL SCOPE RING LAPPING TOOL 1"

Sinclair INTERNATIONAL HAND DIE MICROMETER SEATER TOP

Sinclair INTERNATIONAL LARGE DISPLAY DIGITAL CALIPERS 6"

Sinclair INTERNATIONAL FLASH HOLE DEBURRING TOOL WITH HANDLE PILOTED 17/20 CALIBER

Sinclair INTERNATIONAL BIPOD ADAPTER DELUXE RAIL

Sinclair INTERNATIONAL CASE MOUTH DEBURRING TOOL WITH HOLDER

Sinclair INTERNATIONAL VLD (VERY LOW DRAG) CHAMFERING TOOL

Sinclair INTERNATIONAL SHOOTING REST LIGHTWEIGHT HANDWHEEL STAINLESS STEEL

Sinclair International Dial Indicator Precision Reloading Tool

Sinclair INTERNATIONAL PRIMER POCKET UNIFORMER CARBIDE PPC/BR

Sinclair INTERNATIONAL PRIMER POCKET UNIFORMER CARBIDE SMALL RIFLE/PISTOL

Sinclair INTERNATIONAL TRIMMER CUTTER STANDARD CASE

Sinclair Bolt Stop Remington Black Gunsmithing Tool

Sinclair INTERNATIONAL F-CLASS SHOOTING REST LEG SCRES EXTENDED

Sinclair INTERNATIONAL BOLT STOP FOR REMINGTON ACTIONS SILVER

Sinclair INTERNATIONAL BRASS CASE BRITE MEDIA TREATED WALNUT 5 POUNDS

Sinclair INTERNATIONAL UNIVERSAL SHELLHOLDER HEAD

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.