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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 (2,387)
Sierra 8900 Pro-Hunter 45 Cal .458 300 GR HPFN 50 Per Box
Sierra 8835 Sports Master .45 Cal 185gr JHP Bullets 100/Box
Sierra 8830 Sports Master .45 Cal 300gr JSP Handgun Bullets 50ct
Sierra Bullets 8825 45 Cal 200gr Tournament Master FPJ 100/Box
Sierra 8820 Sports Master .45 Cal 240gr Jacketed Hollow Cavity 100/Box
Sierra 8815 Tournament Master 45 Cal 230gr FMJ Bullets 100/Box
Sierra 8805 Sports Master 45 Cal 230gr JHP 100/Box
Sierra 8800 Sports Master .45 Cal .4515 185 gr JHP 100 Per Box
Sierra 8760 Pro-Hunter 45Cal 260gr Flat Nose Bullets 100/Box
Sierra 8630 Sports Master .44 Cal .429 300gr JSP Handgun Bullets 50ct
Sierra 8620 Sports Master 44Cal 210gr Jacketed Hollow Cavity 100/Box
Sierra 8610 Sports Master 44 Cal .4295 240 gr Jacketed Hollow Cavity (JHC) 100 Per Box
Sierra 8600 Sports Master 44 Cal 180gr JHC 100/Box
Sierra 8520 Sports Master .41 Cal 210gr JHC Bullets 100ct
Sierra 8500 Sports Master .410 Cal 170 Gr JHC Bullets, 100 Count
Sierra Sports Master Handgun Bullets .40 180 gr JHP 100 count
Sierra 8445 Sports Master 10mm Auto .400 165 gr JHP 100 Per Box
Sports Master 10Mm (.401") Jacketed Hollow Point Handgun Bullets 8430
Sierra 8360 Sports Master 38 Cal .357 158 gr JHC 100 Per Box
Sierra 8340 Sports Master 38 Cal .357 158 gr JSP 100 Per Box
Sierra 8325 Sports Master .38 Cal 140gr JHC Bullets 100/Box
Sierra 8320 Sports Master 38 Cal 125gr JHP 100/Box
Sierra 8310 Sports Master 38 Cal 125gr JSP 100/Box
Sierra 8125 9mm 125gr JHP Sports Master Bullets 100ct
Sierra Bullets 8124 9mm 124 Grain Jacketed Hollow Point 100 Count
Sierra 8120 Tournament Master 9mm .355 125gr FMJ Bullets 100ct
Sierra 8115 Tournament Master 9mm 115gr FMJ Bullets 100/Box
Sierra 8110 Sports Master 9mm 115gr JHP Bullets 100/Box
Sierra 8105 Tournament Master 9mm .355 95gr FMJ Bullets 100ct
Sierra 8100 Sports Master 9mm .355 90 gr JHP 100 Per Box
Sierra 8030 Sports Master 32 Cal .312 90 gr JHC 100 Per Box
Sierra 8005 Sports Master .308 Win 85gr Round Nose Bullets 100/Box
Sierra Tipped MatchKing 7775 .30 Caliber 175 Grain Boat Tail Bullet 100 Cou
Sierra .30 Cal 168gr Tipped MatchKing Bullet - 100/box
30Cal 155Gr TMKMAT Rifle Bullets - 100 Count Box
Sierra Tipped MatchKing 7725 .30 Caliber 125 Grain 100 Count Bullets
Sierra Bullets 7685 7MM .284 185GR Tipped Match Grade
Sierra 7mm .284 160gr Tipped MatchKing 100ct Precision Bullets
Sierra 6.5mm 130 gr Tipped MatchKing Rifle Bullets
Sierra Tipped MatchKing 6.5mm 107gr HPBT Rifle Bullets - 100ct 7407
Sierra 7295 Tipped MatchKing 6mm 95gr Rifle Bullets 100/Box
Sierra 7207 6mm .243 107Gr Tipped Match Grade Bullet
Sierra 7188 .22 88Gr Tipped Match Grade Reloading Bullets
Sierra 7177 Tipped MatchKing .22 Caliber 77 Grain Bullet 100 Count
Sierra 7170 .22 Cal 69Gr Tipped Varmint King Bullets
Sierra Bullets .22 Caliber .224 69 Grains HP-BT Match TMK 100CT
Sierra 7160 Tipped MatchKing 22 Caliber 60 Grain 100 Count Bullets
Sierra 5400 Sports Master .50 Cal 400gr JSP Handgun Bullets 50ct
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 E26R-9-BSS-FBZ P226 Full-Size 9mm 4.4" 2-Tone Bron
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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