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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 P226 Full Size Legion SAO 9mm Luger 4.40" 10+1 Gray Cerakote Black G10
Sig SAUER Juliet6 Magnifier 6x24mm Powercam QR Mount Black
Sig Sauer Juliet3 3x24mm Magnifier with PowerCam QR Mount, Black
Sig Sauer 2401191R Picatinny Stock Adapter for AR-15, Aluminum, Black
Sig SAUER P320 ASP .177 Cal 20rd 2-Pack Air Pistol Magazine (AMPC-177-20)
SIG SAUER P320 Black Flat Trigger, 90 Degree Break
Sig Sauer P210 Target 9mm 8 Round Detachable Magazine Blued
Sig Optics Reflex Sight Romeo1 3 MOA 1X30 Standalone Black
Sig SAUER SOR1MK014 Romeo 1 Keymod Mounting Kit AR-15
Sig SAUER SOR1MK012 Romeo 1 Mounting Kit SW M&P 40 Core
Sig Sauer ROMEO1 Glock Mounting Kit - Black Polymer, 1-Piece, SOR1MK011
Sig SAUER SOR1MK004 Romeo 1 Mounting Kit for Smith & Wesson M&P
Sig SAUER SOR1MK003 Springfield XD Romeo1 Handgun Mounting Kit
Sig Sauer SOR1MK001 Romeo1 Handgun Mounting Kit for Glock Black
Sig SAUER 45ACP Medium Black Carry Grip Module Assembly - GRIP-MOD-CA-45-M-BLK
Sig Sauer Elite Match Rifle Ammunition 6.5mm Creed
Sig Sauer HT Elite Hunting 6.5 Creedmoor 120gr Rifle Ammo 20 Rounds
SIG SAUER Elite Copper Hunting .300 Win Mag 165 gr 3110 fps 20 Rounds
Sig SAUER BR2018 270 Winchester Brass 50/Bag
Sig SAUER 1911 BB-Gun .177 Cal 16Rd Black Magazine 2-Pack (AMPC-BB-16)
Sig Sauer BR2030 .308 Win Unprimed Rifle Brass Cases, 50 Count
Sig Sauer BR2029 Component Brass 300 BLK, 50 Count
Sig Sauer BR2005 Unprimed Rifle Brass .22-250 Rem 50 Count
Sig Sauer BP1011 .45 Auto Unprimed Brass Cases, 100 Count
Sig Sauer BP1010 10mm Auto Unprimed Brass 100ct OAL 5.90 In
SigArms BP1009 .40 S&W Brass Cases 100 Count Reloading Supplies
Sig Sauer 9mm Luger Unprimed Brass Handgun Cartridge Cases 100ct - BP1003
Sig Sauer Unprimed Brass Handgun Cartridge Cases .380 Auto 100/ct
Sig Sauer 308 Win 175gr OTM Ammo 20rds E308M2-20
Sig Sauer Elite Copper Hunting .308 Win 150gr Ammo
Sig Sauer Romeo 4 T Red Dot Sight 1x20mm Black 2 MOA 7075 Aluminum
ROMEO4S Ballistic PLX SOL - 0.5 MOA Adjustment Grip
Sig Sauer SRD22X 22 LR Suppressor 5.8 in Titanium 1/2x28 Direct Thread
Sig Sauer 1911 Pistol 10mm 8 Round Black Detachable Magazine
Sig Sauer SOK20001 Tripod Adapter Sleeve Black Aluminum for Kilo 2000 Series
Sig Sauer Juliet4 Magnifier 4x24mm Black Quick Release Mount
Sig Sauer MAG-MOD-F-43-18 P320 40/357 18-Round Magazine
Sig Sauer P320 RSA-320F-9 Full Size 9mm Luger Recoil Spring Assembly
Sig Sauer P320 RSA-320F-4035745 Full Size Recoil Spring Assembly
Sig SAUER P320/P250 .357 SIG Full Broached Black Small Barrel - BBLMODF357
Sig Sauer P320/P250 Compact 3.9" 40 S&W DLC Broached Barrel - Black Nitron Finish
Sig SAUER P320/P250 .40SW Full Broached Black Small Barrel
SigTac P250/P320 FullSize Magazine 9mm 21 Rounds Md: MAG-MOD-F-9-21
Sig Sauer MPX 9mm 10-Round Magazine Gen2 Keymod
Sig P938 Emperor Scorpion Micro-Compact: Steel Barrel, PVD FDE, SigLite, G-10 Grip
Sig P238 Emperor Scorpion Micro-Compact: Stainless Slide, FDE Frame, G-10 Grips
Sig Sauer P320 Compact 9mm Semi-Auto Pistol Black
Sig Sauer M11-A1 Compact 9MM Pistol: 3.9" Barrel, Alloy, Nitron, SIGLITE Sights, 15Rd, SRT, 3 Mags
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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