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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 (2,384)
Sig Sauer Defensive Rifle Ammo 300 Blackout 194 gr. Max Expansion 20 rd.
Sig Sauer Defensive Rifle Ammo 300 Blackout 110 gr. Tac-TX 20 rd.
Sig Sauer Match Grade Rifle Ammo 300 Blackout 125 gr. OTM 20 rd.
Sig Sauer Target Rifle Ammo 300 Blackout 125 gr. Closed Tip Target 20 rd.
Sig Sauer P226 X-Five Extreme Semi-automatic Single Action Only Metal
Sig Sauer P226 X-Five Extreme Semi-automatic Single Action Only Metal
Sig Sauer P226 X-Five Nightmare Semi-automatic Single Action Only Metal
Sig Sauer MCX Pellet CO2 Rifle Black .177 Cal. 30 rd.
SilencerCo AC698 .30 Cal Flash Hider Premium Accessory
SilencerCo AC236 .223 Flash Hider Premium Accessory
SIG Sauer P365 Fuse Tequila 9mm 21Rd Optics Ready
SIG Sauer P365 X-Macro 9mm 17Rd Optics Ready Bronze
SIG Sauer P365 Typhoon 9mm 10Rd Optic Ready Compact
SIG Sauer P365X 9mm 12Rd Optics Ready Compact Pistol
SIG Sauer P365 XMacro 9mm 17Rd Night Sights Silver
Sig P365 380ACP 3.1 OR (2) 12RD BLK COMP MS
Sig Sauer 365XL380COMP 380ACP 12Rd Optics Ready Black
Sig CAL-X KIT P320-M18 9MM CARRY COYOTE 10RD
Sig CAL-X KIT P320-M18 9MM CARRY COYOTE 17/21RD
Sig CAL-X KIT P320-M17 9MM FULL COYOTE 10RD
Sig CAL-X KIT P320-M17 9MM FULL COYOTE 17/21RD
Sierra Pro-Hunter Rifle Bullets 22 cal 77gr HPBT 500/ct
Sierra 7mm 185gr Tipped MatchKing Bullets 500/Box
Sierra 7207C 6mm 107Gr Tipped MatchKing 500 Box
Sierra Tipped MatchKing 22 cal 88gr Bullets 500/ct
Sierra 22 Caliber 69 Grain Tipped GameKing Bullets 500/Box
Sierra MatchKing Bullets 6mm 105gr HPBT/CN 500/ct
Cytac T THUMBSMART HOLSTER SIG SAUER P320 CARRY
Sig Sauer Mag Adapter 9mm 40 High Cap M&P Compatible
SilencerCo AC1496 Alpha Direct Thread Mount Black 3/4x24 for 300 Win Mag
SilencerCo AC1526 Adapter Fixed Barrel Mount for Sig MPX Attachment for Octane 9&45 Interchange W/ Octane Mounts 13.5x1mm LH FOR OCTANE SILENCERS
SilencerCo AC1413 Hybrid 45 End Cap 45 Caliber .458 CAL
SilencerCo AC150 Adapter Fixed Barrel Mount for Octane Attachment for Octane 9&45 Interchange W/ Octane Mounts 1/2x36 COLT SMG MOUNT FOR OCTANE
SilencerCo AC2606 Adapter Matte Black 3-Lug Male Adapter Fits .45ACP Caliber Guns 9/16x24
Sig Sauer P365 Fuse Semi-automatic Striker Fired Polymer Frame Pistol
Sig Sauer P365 Fuse Semi-automatic Striker Fired Polymer Frame Pistol
Sig SAUER 365XF-9-DH3-RXSL P365 DH3 9mm 3.7" Coyote Semi-Auto Pistol
Sig Sauer P211 GTO Handgun 9mm Luger 23(1)&21(1) Magazines 4.4 Barrel Sig Loc
Sig SAUER 365XF-9-DH3-10 P365 DH3 9mm 3.7" Coyote Semi-Auto Pistol
Sig SAUER 365XF-9-DH3 P365 DH3 9mm 3.7" Coyote Semi-Auto Pistol
Sig SAUER 365AXGF-9-DH3-10 P365 DH3 9mm 3.7" Coyote Semi-Auto Pistol
Sig SAUER 365AXGF-9-DH3 P365 DH3 9mm 3.7" Coyote Semi-Auto Pistol
Sig SAUER 365XF-9-CFO-2A P365 Fuse 9mm 4.3" Nitron Semi-Auto Pistol
Sig SAUER 365XF-9-CTAC-TB-RXSL P365 Tacops 9mm 5.1" Nitron Semi-Auto Pistol
Sig Sauer P365X-Macro TACOPS Handgun 9mm Luger 21rd Magazines(4) 4 Threaded Barrel Romeo-X Red Dot
Sig SAUER 8901964 P320 Magazine 9mm 23 P211/P320 8901964
Sig SAUER 365X-9-BXR3P-MS-MA P365X 9mm 3.1" Nitron Semi-Auto Pistol
Sig Sauer SOW63116 Whiskey 6 MRAD Black Adjustable Scope
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 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
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
Sig SAUER 365XF-9-CFO-2A P365 Fuse 9mm 4.3" Nitron Semi-Auto
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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