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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 (2,382)
Sig Sauer E223M120 Marksman 223 Rem 77 gr OTM Ammo
Sig SAUER Elite Performance Match Grade 300 Win Mag 190gr 20rd Box OTM Ammo
Sig Sauer Elite Match Rifle Ammunition .308 Win 16
Sig Sauer MAG-225A-9-8 P225A 9mm 8-Round Blued Steel Magazine
SIG SAUER 1913 Interface Folding Knuckle Stock Adapter (ADAPTER-X-FOLD)
Sig Sauer P320 P250 Carry Grip Module Assembly Large Black
Sig Sauer P320 P250 Grip Module Assembly 9mm .40 .357 Black Small
Sig SAUER P320 Compact/Carry 357 SIG 3.9in No LCI Barrel (BBL-MOD-C-357)
Sig Sauer 1300926-R P320 Striker Assembly
Sig Sauer Taper Cap 7.62 Barrels 5-8-24 Thread
Sig Sauer Taper Cap 5.56NATO 1/2x28 Thread Anodized Black
Sig Sauer P210 Target 9mm Pistol Black 5" Barrel Walnut Grip
Sig SAUER MCX/MPX Collapsible/Telescoping Stock STOCK-X-COLLAPSIBLE-BLK
Sig Sauer AMRC-22-30 Airgun Magazine .22 Cal 30Rd MCX/MPX 3 Belts
Sig Sauer AMRC-177-30 Airgun Magazine .177 Caliber 30 Rounds Polymer Compos
Sig Sauer P226/P250 Air Pistol Magazine 16-Round .177 Caliber 2-Pack
Brownells SIG SAUER 320 Subcompact Inner Recoil Spring Parts
Sig Sauer 1911 Style Magazine 9mm 8 Rounds
Sig Sauer P320 Sub-Compact 9mm Barrel 3.6" Black Nitride Steel
Sig Sauer P320C 9mm Threaded Barrel - BBLMODC9TB
Sig Sauer BBLMODC9 P320 Barrel 9mm Luger 3.90 Inch Nitride Steel
Sig Sauer P320 9mm 4.7" Barrel Black Nitride Steel
Sig Sauer P320 Multi-Caliber Recoil Spring Assembly
Sig Sauer E45AP1-50 V-Crown 45 Auto 230GR JHP 50 Rounds Box
Sig Sauer E40SW1-50 Elite V-Crown .40 S&W 165gr JHP Ammo 50 Rounds
Sig Airguns Advanced Sport Pellet Replacement 2-Pa
Sig Sauer AC1240 CO2 Cartridges, 12g, 40-Pack, Silver
Sig Sauer AC1215 CO2 Cartridge 12 Gram 15 Pack Airgun Accessory
Sig Sauer Airguns AC125 CO2 Cylinders 12g 5 Pack
Sig Sauer P320 P250 Carry Grip Module Assembly 9mm 40 S&W 357
SigTac P220 Magazine 10mm 8 Round Md: MAG-220-10-8
Sig Sauer Airgun Target Dual Shooting Gallery
Sig Sauer Airgun P226 .177 Cal 12Gr Co2 16 Rd Blac
Sig Sauer SRD Piston M16x1 LH 17-4 Stainless Steel Black
Sig Sauer SRD-PISTON-578X28 .45 ACP Suppressor Piston Stainless Steel
SigArms SRD-PISTON-M135X1LH 9MM 13.5x1mm LH Stainless Steel Matte Finish
Sig Sauer Suppressor Piston 1-2-28 Thread Compatible with SRD9 SRD45
Sig Sauer SOX10008 X-Ray3 Sight Set Green Day/Night #8 Front/#6 Rear
Sig Sauer SOX10007 X-Ray3 Sight Set Green Day/Night #8/#6 Square Notch
Sig Sauer SOX10006 X-Ray3 Sight Set Green Day/Night #6 Front/Rear
SigArms X-RAY3 Sights #6 Front #6 Rear Square Notch Green Tritium
SIG SAUER X-Ray3 Pistol Sight Set Green Front Rear Round Notch
Sig Sauer X-Ray3 Pistol Sight Set Green Front Rear Square
Sig SAUER X-Ray3 Pistol Sight Set #6 Green Front #8 Rear
Sig Sauer SOX10001 X-Ray3 Sight Set #6 Green Front #8 Rear Square Notch
Sig Sauer 320 SEAR SPRING
Sig Sauer 1300675-R Trigger Bar P320
Sig Sauer Alpha1 Tactical Scope Ring Set 30mm Cantilever Aluminum
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.
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
Sig Sauer P365 9mm 3.1 Inch NITRON Striker Fired Compact Han
Sig Sauer P226 X-Five Extreme Semi-automatic Single Action O
Sig Sauer P226 Magazine 10rd 40 S&W/357 SIG Stainless Steel
Sig Sauer WRMCX-556N-9B-LT-SBR MCX SBR 223 Rem | 5.56 NATO 9
Shop SI Products
Sig SAUER MCX-SPEAR 6.8x51mm SBR 13in Semi-Auto Rifle RSPEAR
Sig Sauer P320 FLUX 9MM 3.9" 30RD Legion 320
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
Sierra 1502 BlitzKing Rifle Bullets 6mm .243 55gr 100ct
Sierra MatchKing-X Rifle Bullets .30 Cal 175 gr HPBT 500/ct
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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