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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 (2,385)
Sig SAUER 365XL-9-ROSE-MS-RS P365 Rose XL Comp 9mm 3.7" Nitron Semi-Auto Pistol
Sig SAUER 365-380-ROSE-MS-RS P365 Rose Romeo-RS 380 ACP 3.1" Nitron Semi-Auto Pistol
Sig Sauer P365 9MM 25 Magazine Black Baseplate Orange Follower
Sig Sauer P365 9MM 25 Factory Magazine Black Baseplate
Sig SOZFNS0M ZULU FLOATING NECK STRAP BINO
Sig P365 9MM 3.1 X-SERIES 10RD SIG-LOC
Sig SAUER 320X5-10-BXR3-RXSL P320 XTEN 10mm 5" Nitron Semi-Auto Pistol
Sig Sauer SOW63115 Whiskey 6 Black Adjustable Scope
SIG SAUER SOEC32310 Echo RV50 Thermal Riflescope Matte Black 640x512 Core SOEC32310 | 2.5-20X50MM
Sig Sauer Echo RV35 Thermal Riflescope 2 16x35mm Black
Sig Sauer SOEC31200 Thermal Riflescope 3.5-28X35 Black
Sig Sauer 320XC9BXR3RXP10 P320 XCompact 9mm Luger 3.60" 10+1 Black Black Nitron Stainless Steel Black Polymer Grip
Sig Sauer P365 Tiger Stripe Black XMACRO TACOPS Handgun 9mm Luger 17rd Magazines(4) 3.7 Barrel
MANTIS SIG SAUER P365 10RD MAGRAIL
Comp-Tac C241SS263RBKN International Black Kydex OWB Sig Sauer P365 XL Right Hand
Comp Tac Warrior Holster OWB Stealth Sig P365 Black
Sierra BlitzKing Bullets 22 cal 69gr TVK 500/ct
Sierra BlitzKing Bullets .204 36gr TVK 20 cal 500/ct
Sierra MatchKing (MKX) Rifle Bullets 6mm 107 gr HPBT MKX 100/ct
Dead AIR KEY-MO MOUNT FOR SILENCERCO OMEGA
Sig Sauer P365 Fuse Semi-automatic Polymer Frame Pistol Compact 9MM 4.3"
Sig Sauer P365 Semi-automatic Striker Fired Polymer Frame Pistol Compact
SilencerCo AC4741 Charlie Direct Thread Mount 11/16x24
Sig Sauer SIERRA 30mm Main Tube/ BDX-R2 Digital Ballistic Reticle Matte
Sig Sauer SIERRA 30mm Main Tube/ BDX-R2 Digital Ballistic Reticle Matte
Sinclair INTERNATIONAL BULLET COMPARATOR 7MM (0.284")
Sinclair INTERNATIONAL BULLET COMPARATOR 6.5MM (0.264")
Sinclair INTERNATIONAL BULLET COMPARATOR 338 CALIBER (0.338")
Sinclair INTERNATIONAL DIGITAL INDICATOR
Sinclair INTERNATIONAL AR-15 CARRIER KEY BRUSH
Sierra SPR Polymer Black Tactical Handgrip Accessory
Sinclair INTERNATIONAL DIGITAL INDICATOR W/ LEVER AND FLAT POINT
Sinclair INTERNATIONAL DELUXE SHOOTING REST FOREND STOP
Sinclair INTERNATIONAL DELUXE SHOOTING REST THREADED HANDWHEEL 1-14"
Sinclair INTERNATIONAL DELUXE SHOOTING REST THREADED POST 1-14"
Sinclair INTERNATIONAL TIN COATED TURNING MANDREL 338 CALIBER (0.336")
Sinclair INTERNATIONAL TIN COATED TURNING MANDREL 8MM (0.321")
Sinclair International 30 Cal Tin Coated Turning Mandrel
Sinclair INTERNATIONAL TIN COATED TURNING MANDREL 7MM (0.282")
Sinclair INTERNATIONAL TIN COATED TURNING MANDREL 270 CALIBER (0.275")
Sinclair INTERNATIONAL TIN COATED TURNING MANDREL 6.5MM (0.262")
Sinclair INTERNATIONAL TIN COATED TURNING MANDREL 25 CALIBER (0.255")
Sinclair International 22 Cal Tin Coated Turning Mandrel
Sinclair INTERNATIONAL TIN COATED TURNING MANDREL 20 CALIBER (0.202")
Sinclair INTERNATIONAL TIN COATED TURNING MANDREL 17 CALIBER (0.170")
Sinclair INTERNATIONAL TIN COATED EXPANDER MANDREL 338 CALIBER (0.337")
Sinclair INTERNATIONAL TIN COATED EXPANDER MANDREL 8MM (0.322")
Sinclair International 7mm Tin Coated Expander Mandrel
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 W365XL-9-BXR3P-MS P365 XL 9mm 3.7" Nitron Semi-Aut
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
Sierra Bullets 4540C 7mm 0.284 Caliber 140 Grain Tipped Boat
SilencerCo AC1278 ASR Black Nitride 9/16"x24 LH Threads 30 C
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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