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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

2,365

In Stock

Founded

USA

Origin

All SI Products (2,365)

Sinclair International Bore Brush 375 Caliber

Sinclair International Rifle Bore Brush 338 8-32M

Sinclair International Bronze Rifle Bore Brush 8mm

Sinclair INTERNATIONAL ROD CASE BRACKET

Sinclair INTERNATIONAL THOMPSON CENTER ROD GUIDE FOR 35 REMINGTON

Sinclair INTERNATIONAL THOMPSON CENTER ROD GUIDE FOR 6.5X284 WINCHESTER

Sinclair INTERNATIONAL SOLVENT BOTTLES BARRIER TYPE 4OZ 3 PACK

Sinclair INTERNATIONAL ACTION CLEANING TOOL HEAD FOR KIMBER/SMALL SAKO

Sinclair INTERNATIONAL ACTION CLEANING TOOL COTTON ROLLS 50 PACK

Sinclair International Scope Ring Lapping Tool Combo Kit

Sinclair INTERNATIONAL TRIMMER CUTTER POWER ADAPTER

Sinclair INTERNATIONAL NECK TURNING HANDLE LARGE 35-50 CALIBER

Sinclair INTERNATIONAL PRIMER POCKET UNIFORMER KIT WITH SCREWDRIVER

Sinclair INTERNATIONAL CASE TRIMMER POWER ADAPTER

Sinclair INTERNATIONAL LARGE CALIBER NECK TURNING MANDREL SS 408 CALIBER

Sinclair INTERNATIONAL LARGE CALIBER NECK TURNING MANDREL SS 375 CALIBER

Sinclair INTERNATIONAL LARGE CALIBER STAINLESS EXPANDER MANDREL 408

Sinclair INTERNATIONAL SOLVENT BOTTLE WITH FLIPTOP LID 4OZ 3 PACK

Sinclair INTERNATIONAL BENCHREST COMPETITION SHOOTING REST NON-WINDAGE

Sinclair INTERNATIONAL BULLET SORTING STAND WITH DIGITAL INDICATOR

Sinclair International Competition Shooting Rest Premium

Sinclair INTERNATIONAL TRIMMER STAND WITH SHARKFIN CLAMP

Sinclair INTERNATIONAL NECK TURNING CASE HOLDER #7 338 LAPUA MAGNUM

Sinclair INTERNATIONAL DIE LOCK RING PLIERS FOR HORNADY & LEE PRECISION

Sinclair International Bullet Comparator 22 Caliber Precision

Sinclair INTERNATIONAL BULLET SEATING DEPTH GUIDE AR-15

Sinclair INTERNATIONAL PILOT STOP STAINLESS STEEL 408 CALIBER

Sinclair INTERNATIONAL PILOT STOP STAINLESS STEEL 422 CALIBER

Sinclair INTERNATIONAL BENCHREST SHOOTING REST WINDAGE TOP RIGHT HAND

Sinclair INTERNATIONAL BENCHREST SHOOTING REST WINDAGE TOP LEFT HAND

Sinclair INTERNATIONAL PREMIUM NECK TURNING TOOL WITH HANDLE NT-4000

Sinclair INTERNATIONAL PREMIUM NECK TURNING TOOL ONLY NT-4000

Sinclair INTERNATIONAL TRIMMER MICROMETER ATTACHMENT

Sinclair INTERNATIONAL SHOOTING REST SPEED SCREW 3/8"X16 THREADS

Sinclair INTERNATIONAL CARBIDE NECK TURNING MANDREL 6.5MM (.262")

Sinclair INTERNATIONAL CARBIDE NECK TURNING MANDREL 20 CALIBER (.202")

Sinclair INTERNATIONAL CARBIDE NECK TURNING MANDREL 270 CALIBER (.275")

Sinclair INTERNATIONAL CARBIDE NECK TURNING MANDREL 17 CALIBER (.170")

Sinclair INTERNATIONAL OFFSET SCOPE LEVEL 1" MATTE BLACK

Sinclair INTERNATIONAL PRIMER POCKET UNIFORMER CARBIDE LARGE RIFLE

Sinclair INTERNATIONAL AR-15 CHAMBER BRUSH ROD KIT

Sinclair INTERNATIONAL SHARKFIN CLAMP ATTACHMENT

Sinclair INTERNATIONAL NECK TURNING HANDLE STANDARD 17-338 CALIBER

Sinclair INTERNATIONAL DIE LOCK RING PLIERS FOR REDDING

Sinclair INTERNATIONAL NECK TURNING CASE HOLDER #3 308 FAMILY

Sinclair International Neck Turning Case Holder Magnum

Sinclair INTERNATIONAL NECK TURNING CASE HOLDER #1 223 FAMILY

Sinclair INTERNATIONAL CASEHOLDER DRIVER

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.