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SI designs rugged, user-focused firearm components and optics. They make accessories like slide plates, charging handles, barrel clamps, red dots, and shotgun parts.
All SI Products (2,390)
Sinclair 050806110878 Case Neck Wall Thickness Micrometer
Sinclair International 050806110861 Stainless Steel Priming Tool
Sinclair International 050806110823 Heavy Varmint Rest
Sinclair International AR-15/308 AR Lug Recess Cleaning Equipment
Sig SAUER, INC. P365-XMACRO TACOPS 9MM 3.7"BBL (4)17RD BLACK MULTI CAMO
Sig SAUER, INC. P365-XMACRO TACOPS 9MM 3.7"BBL (4)17RD BLUE MULTI CAMO
Sig SAUER, INC. P365-XMACRO TACOPS 9MM 3.7" BBL (4)17RD WHITE MULTI CAMO
Sinclair INTERNATIONAL EJECTOR SPRING TOOL FOR REMINGTON RIFLES
Sinclair INTERNATIONAL MAINSPRING TOOL FOR REMINGTON RIFLES
Sinclair 050806002739 Remington 700 Bolt Maintenance Tool Kit Case
Simmons 511039 22 Mag Matte Black 3-9x 32mm 1" Tube Truplex Reticle
Simmons 8-Point 3-9x50 Riflescope Truplex Reticle Matte Black Finish
Simmons Optics SPH1000 Pro Hunter Laser Rangefinder Black Rubber Armored Tilt Angle Range Compensation 1,000 yrd Range
Simmons SPTA432 ProTarget 4x32mm Rifle Scope
Simmons SPTTD120 Pro Target Red Dot Matte Black 1x20mm Tube
Simmons Pro Target Reflex Sight 1x25mm 4MOA Red Dot - Matte Black SPTRD125
Simmons Pro Target Air 3-9x40 Rifle Scope 1" SFP I
Simmons SPTA2732 ProTarget 2-7x32mm Rifle Scope
Simmons SPR3932 ProTarget Rimfire 3-9x32mm Scope
Simmons SPR432 ProTarget Rimfire 4x32mm Scope
Simmons SPH61850 ProHunter 6-18x50mm Rifle Scope
Simmons SPH41240 ProHunter 4-12x40mm Rifle Scope
Simmons SPH3950 ProHunter 3-9x50mm Rifle Scope
Simmons SPH3940 ProHunter 3-9x40mm Rifle Scope
Simmons SPH1250 ProHunter 12x50mm Matte Binoculars
Simmons SPH1050 ProHunter 10x50mm Matte Binoculars
Simmons SPH1042 ProHunter 10x42mm Matte Binoculars
Simmons SPH842 ProHunter 8x42mm Matte Binoculars
Simmons Spotting Scope 20-60X60 Tripod Hard/Soft Case
Simmons Venture 10x42mm Binoculars Roof Prism Black Rubber Armor
Simmons Venture Spotting Scope 15-45x60mm Straight Black
Simmons ProTarget Matte Black 6-24x 44mm 30mm Tube Mil-Dot Reticle
Simmons ProTarget Matte Black 4-16x40mm 30mm Tube Mil-Dot Reticle
Simmons SIM41240C ProTarget Black 4-12x 40mm Rifle Scope
Simmons SIM3940C ProTarget Black 3-9x40mm Scope
Sinclair 00252882 Double Headed Cotton Swabs 100 Pack
Sinclair H-4W Hook and Pick Set, Durable Steel Construction
Sig Sauer P365 Handgun Magazine 9mm Luger 10/rd Bulk
About SI
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.
Notable Products
Popular items include charging handles, slide adapter plates, red dot sights, barrel clamps, and shotgun conversion components.
Why Choose SI?
Choose SI for straightforward, well-engineered accessories that improve usability and durability without unnecessary complexity.
Hot SI Items June 2026
Trending right now based on the last 30 days of TheGunDock orders + page views.
SilencerCo Sparrow 22 Rimfire Suppressor 22LR 5.08" Stainles
SIG SAUER 322C-ROSE-RS P322 Rose 22 LR 4" Black Anodize Semi
Sig Sauer Tango-MRS Compact Rifle Scope 1-6x24 30mm SFP BDC6
Sig Sauer Cross Sawtooth Rifle 6.5 PRC 22 inch Moss Green Fo
Sig Sauer W365XL-9-BXR3P-MS P365 XL 9mm 3.7" Nitron Semi-Aut
Sig Sauer 2401191R Picatinny Stock Adapter for AR-15, Alumin
Sig Sauer SORX1080 24MM Black Pro Optics Ready Sight
Sig Sauer W365XL-9-BXR3P-RXX P365 XL Romeo-X 9mm 3.7" Nitron
Shop SI Products
Sig SAUER MCX-SPEAR 6.8x51mm SBR 13in Semi-Auto Rifle RSPEAR
SilencerCo Sparrow 22 Rimfire Suppressor 22LR 5.08" Stainles
Sig Sauer P320 FLUX 9MM 3.9" 30RD Legion 320
Sig Sauer SLH300TIQD 300 Blackout Titanium Suppressor
SilencerCo Velos LBP 5.56 NATO/.223 4.76 In Low Back-Pressur
SIG SAUER MCX Spear SBR 7.62x51mm 13" Nitride NFA
Sig Sauer P365X Macro Tacops 9mm 3.7" 17rd Pistol
Sinclair INTERNATIONAL DIAL INDICATOR .001
Sig Sauer ROMEO1 Black Shroud Kit SOR1SK001: Medium Size, Ne
Sig Sauer 8900823 LTXG Grip Module Laser Engraved P320-X Car
Sig Sauer MCX-SPEAR LT AR Conversion Kit 5.56 NATO 11.5" Bla
Sig SAUER MCX 5.56 NATO 16in 30rd IR Cerakote FDE Rifle RMCX
SI News & Articles
Firearm Shipping Restrictions by State (2026 Update)
State-by-state guide to firearm and ammunition shipping for online buyers and FFL dealers. Current as of May 2026. Cover...
Damaged in Transit: How TheGunDock Handles Shipping Claims on Firearms and Ammo
When a firearm or ammo shipment arrives damaged, the claim process matters. TheGunDock walks through what to do, what we...
The Springfield KUNA: Roller-Delayed 9mm Pistol That's Shaking Up the PDW Market
The Springfield Armory KUNA — a roller-delayed 9mm pistol built in partnership with Croatia's HS Produkt — has becom...
The Strait of Hormuz: 2,500 Years of Trade, Arms, and Conflict
A twenty-one-mile-wide choke point has shaped the movement of goods — and weapons — across half the ancient and mode...
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Choose SI for straightforward, well-engineered accessories that improve usability and durability without unnecessary complexity....
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