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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 Bullets 1742C 6.5mm 142gr HPBT MatchKing 500/Box
Sierra 1740C MatchKing Rifle Bullets 6.5mm/.264 140gr HPBT 500ct
Sierra Bullets 1729C 6.5mm 130gr Hollow Point BT 500/Box
Sierra Bullets 1727C 6.5mm 123gr HPBT 500/Box
Sierra 1725C 6.5mm 120gr HPBT MatchKing Bullets 500/Box
Sierra 1605C 25 Caliber 70GR Flat Base Bullets 500/Box
Sierra 1575C MatchKing 6mm 110gr Hollow Point Boat Tail 500/Box
Sierra Bullets 1570C 6mm 0.243 in 107 gr HPBT 500 per Box
Sierra 1537C MatchKing 6mm/.243 95gr HPBT Rifle Bullets (500 Count)
Sierra 1507C BlitzKing 6mm .243 70gr Rifle Bullets 500ct
Sierra Bullets 1505C 6mm 70gr HPBT 500/Box
Sierra 1502C BlitzKing Rifle Bullets 6mm .243 55gr 500ct
Sierra BlitzKing .22 Caliber .224 55 Grain Rifle Bullets 500 Count
Sierra 1440C BlitzKing .22 Cal .224 40gr Rifle Bullets 500ct
Sierra MatchKing 1410C .22 Caliber 52 Grain HPBT Match 500 Count
Sierra Bullets 1400C 22 Cal 53gr Hollow Point 500/Box
Sierra Bullets 1396C 22 Cal 95gr HPBT MatchKing 500/Box
Sierra MatchKing Bullets (500/ct) .22 cal .224 69 gr HPBT MATCH - Designed for Service Rifle competition in the M16A2/AR-15A2.
Sierra Bullets 1039C 20 Cal 39gr Boat Tail BlitzKing 500/Box
Sierra Bullets 1032C 20 Cal 32GR Flat Base BlitzKing 500/Box
Sierra MatchKing Bullet .22 Cal 77gr HPBT Cannelured
Sierra 9390T MatchKing 22 Cal 80GR HPBT Bullets 50/Box
Sierra 9377T MatchKing 22Cal 77gr HPBT Bullets 50/Box
Sierra Bullets 9350T 375 Cal 350gr HPBT Rifle Bullets 50/Box
Sierra 9300T MatchKing 338 Cal .338 300 gr HPBT 50 Per Box
Sierra 9290T MatchKing 22Cal 90GR HPBT Bullets 50/Box
Sierra 9240T .30 Cal .308 210GR HPBT MatchKing Bullets 50ct
Sierra 4681T Green Tipped GameKing .30 Cal 180gr Bullets 50ct
Sierra 4665T Tipped GameKing 308 Caliber 165 GR 50 Per Box
Sierra 4610GT Green Tipped GameKing .30 Cal 210gr Bullets, 50/Box
Sierra 4565T 7mm .284 165gr HPBT GameKing Expansion
Sierra 4440T Tipped GameKing 270 Win 140 gr Hollow Point Boat Tail
Sierra 4330T Tipped GameKing 6.5 Creedmoor .264 130 gr Hollow Point Boat-Tail (HPBT) 50 Per Box
Sierra 4100T Tipped GameKing 6mm .243 90gr HPBT 50/Box
Sierra 2237 MatchKing 30Cal 215gr Hollow Point Boat Tail 50/Box
Sierra V-Crown 9mm Luger 90gr JHP Bullets - 100 Count
Sierra Bullets 9947 9mm 147gr JHP V-Crown Pistol Bullets, 100 Count
Sierra V-Crown 9mm Luger JHP 125gr Pistol Bullets - 100 Count
Sierra V-Crown 9mm Luger 124 gr. JHP Bullets - Ultimate Defense Line
Sierra Bullets 9820 .45 Cal 200GR JHP V-Crown 100CT
Sierra MatchKing Rifle Bullets .25 Cal .257 131 gr HPBT/CN 100/ct
Sierra Bullets V-Crown 9465 10mm 165gr JHP 100 Count Box
Sierra 9390 .22 Cal 80gr HPBT Bullets, 500/Box
SIERRA BULLETS .22 CAL .224 77GR HPBT MATCHKING-X
Sierra 9377 .22 Caliber 77 Grain HPBT Bullet 0.224 in 500 Count
Sierra GameKing .22 Caliber 62 Grain Spitzer Boat Tail Hunting Bullets
Sierra 9300 .338 Cal 300gr HPBT Bullets, 500/Box
Sierra 9290 MatchKing 22Cal 90gr HPBT 500/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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