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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 (2,390)
Sierra MatchKing .264 Caliber 130gr Tipped Bullet, 500/box, High Ballistic Coefficient, Reliable Feeding
Sierra Tipped MatchKing 6.5mm 107gr HPBT Bullets - Enhanced Accuracy, 500ct
Sierra Bullets 7295C 6mm 95gr TMK 500/Box
Sierra 7177C Tipped MatchKing .22 Cal .224 77 gr 500 Per Box
Sierra 7169C Tipped MatchKing .22 Cal .224 69 Grain Bullet 500 Count
Sierra 7160C Tipped MatchKing .224 60gr TMK Bullets - 500ct Box for Varmint
Sierra Green Tipped GameKing Rifle Bullets .30 cal .308 180 gr TGK 500/ct
Sierra 4680C Tipped GameKing Rifle Bullets .30 Cal .308 180gr BT 500ct
Sierra Bullets 4625C 30 Caliber 125gr Polymer Tipped 500/Box
Sierra Green Tipped GameKing Rifle Bullets 7mm .284 180 gr TGK 500/ct
Sierra 4550C Tipped GameKing 7mm/.284 150gr BT Rifle Bullets 500ct
Sierra Bullets 4540C 7mm 0.284 Caliber 140 Grain Tipped Boat Tail 500 Count
Sierra 4475C Tipped GameKing .270 Cal 175gr Rifle Bullets, 500/Box
Sierra Green Tipped GameKing Rifle Bullets 6.5mm .264 145 gr TGK 500/ct
Sierra 4340C 6.5mm 140gr Tipped Boat Tail Bullet 500 Count
Sierra 4330C 6.5mm 130gr Tipped GameKing Bullets, 500/Box
Sierra Green Tipped GameKing Rifle Bullets 6.5mm .264 120 gr TGK 500/ct
Sierra 4210C Tipped GameKing .25 Cal 110gr Rifle Bullets, 500/Box
Sierra 4110C Tipped GameKing Rifle Bullets 6mm .243 100gr BT 500ct
Sierra 4062C Tipped GameKing .22 Cal .224 64gr BT Rifle Bullets 500ct
Sierra Pro-Hunter Rifle Bullets .35 cal .355 155 gr FN 500/ct
Sierra Bullets 2650C 338 Cal 250gr HPBT 500/Box
Sierra Bullets 2315C 303 Cal 174gr HPBT 500/Box
Sierra Bullets 2275C 30 Cal 175gr HPBT MatchKing 500/Box
Sierra Bullets 2269C MatchKing HPBT 7.62mm/.30 Cal 169gr 500/Box
Sierra 2251C MatchKing .30 Cal 230gr HPBT Rifle Bullets 500ct
Sierra Bullets 2240C 30 Cal 220gr HPBT MatchKing 500/Box
Sierra MatchKing Rifle Bullets .30 cal .308 215 gr HPBT/CN 500/ct
Sierra 2236C GameKing 30Cal 205gr Hollow Point Boat Tail 500/Box
Sierra Tipped MatchKing-X Rifle Bullets .30 Cal 200 gr HPBT 500/ct
Sierra 2230C MatchKing .30 Cal .308 200gr HPBT Rifle Bullets 500ct
Sierra 2210C 30 Cal 190gr HPBT Bullets 500/Box
Sierra Bullets 2200C 30 Cal 168gr HPBT MatchKing 500/Box
Sierra Bullets 2190C 30 Cal 150gr HPBT 500/Box
Sierra MatchKing-X Rifle Bullets .30 Cal 175 gr HPBT 500/ct
Sierra Bullets 2156C 30 Cal 155gr HPBT Palma 500/Box
Sierra 2155C MatchKing .30 Cal .308 155gr HPBT Rifle Bullets 500ct
Sierra 2136C Varminter Rifle Bullets .30 Cal 150gr HP 500ct
Sierra Bullets 2124C 30 Caliber 135gr Hollow Point 500/Box
Sierra Bullets 2121C 30 Cal 125Gr HP MatchKing 500/Box
Sierra Bullets 2116C 30 Cal 115gr Hollow Point Varminter 500/Box
Sierra 1997C MatchKing 7mm/.284 197gr HPBT Rifle Bullets 500ct
Sierra MatchKing Rifle Bullets 7mm .284 180 gr HPBT/CN 500/ct
Sierra Bullets 1980C MatchKing 7mm (.284) 180gr HPBT 500/Box
Sierra 1930C MatchKing Rifle Bullets 7mm .284 168gr HPBT 500ct
Sierra 1915C MatchKing Rifle Bullets 7mm/.284 150gr HPBT 500ct
Sierra MatchKing-X Rifle Bullets .270 cal 135 gr HPBT 500/ct
Sierra Bullets 1785C 6.5mm 105 Grain Boat Tail 500 Bullets/Box
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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