Buy SI Online
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 (2,385)
Sig Sauer P365/X/XL Handgun Magazine 9mm Luger 12/rd
Sierra GameKing Rifle Bullets .30 cal .308 205 gr HPBT/CN 500/ct
Carbide Primer Pocket UNIFORMERS
Sinterfire Special Duty Pistol Ammo 380 ACP 75 gr. HP 20 rd.
SinterFire SF38110SD 38 Special 110gr Lead-Free Frangible HP Ammo 20/Box
Sinterfire Special Duty Pistol Ammo 9mm 100 gr. HP 20 rd.
SinterFire SF45155SD .45 ACP 155gr Lead-Free Frangible HP Ammo 20/Box
SinterFire SF40125SD .40 S&W 125gr Lead-Free Frangible HP Ammo 20/Box
SinterFire SF10125NXG 10mm Auto 125gr Lead-Free Ammo 50 Rounds
SinterFire SF40125NXG 40 S&W 125gr Lead-Free Ammo 50 Rounds
SinterFire Inc SF9100NXGLF Next Generation (NXG) 9mm 100gr 50 Per Box/20 Case
SinterFire SF38075NXG 380ACP 75gr Lead-Free Ammo 50 Rounds
SinterFire SF9100NXG 9mm 100gr Lead-Free Ammo, 50 Rounds, Brass Case
SinterFire SF10125SD 10mm 125gr Lead-Free Frangible HP Ammo 20 Rounds
SilencerCo AC1757 Threaded Barrel 4.50" .40 S&W Black Nitride Steel
SilencerCo Piston 1/2-28 Stainless Steel
SilencerCo AC1726 Threaded Barrel Glock 43 9mm 1/2x28 Black 3.5"
SilencerCo Threaded Barrel For H&K Vp9 9mm Luger 1
SilencerCo ASR Blast Shield Black Steel
SilencerCo AC1564 Bravo Direct Thread Mount Fits .578"x28 Matte Black
SilencerCo AC1563 Bravo Direct Thread Mount Fits M13.5 x 1 LH Matte Black
SilencerCo Hybrid ASR Flash Hider 9mm Black
SilencerCo ASR Flash Hider M13.5x1 LH 9mm Black
SilencerCo ASR 3-Port Muzzle Brake .458 Caliber Black
SilencerCo Hybrid Front End Cap 9mm Steel Black
SILENCERCO Hybrid Direct 1/2x28 Thread Mount
SilencerCo AC1361 Thread Protector .578"x28 Black Steel 45 ACP
SilencerCo AC1360 Thread Protector 9mm Luger Steel 1-2"-28 tpi AR-Platform
SilencerCo AC1370 Bravo Front Cap 223 Cal Fits Matte FDE
SilencerCo AC1369 Bravo Front Cap 30 Cal Fits Matte FDE
SilencerCo AC1347 Choke Mount Adapter for Salvo 12 Suppressor Black
SILENCERCO Common 1/2x28 /.578x28/M13.5LH /M16x1LH 9/16x24 Piston Kit AC728
SilencerCo Piston AC25 17-4 Stainless Steel for Omega K, Hybrid, Osprey
SilencerCo The Bravo Front Cap 5.56x45mm NATO Black
SILENCERCO Omega 762 Basic Front Cap (AC1340)
SilencerCo AC1328 Echo Choke Adapter Black
SilencerCo AC1327 Echo Choke Adapter Black
SilencerCo AC1326 Echo Choke Adapter Black
SilencerCo AC1325 Echo Choke Adapter Black
SilencerCo AC1324 Echo Choke Adapter Black
SilencerCo AC1323 Echo Choke Adapter Black
SilencerCo AC1322 Echo Choke Adapter Black
SilencerCo AC1315 Echo Choke Adapter Black
SilencerCo AC1320 Echo Choke Adapter Black
SilencerCo AC1312 Echo Choke Adapter Black
SilencerCo AC1311 Echo Choke Adapter Black
SilencerCo AC1310 Echo Choke Adapter Black
SilencerCo AC1308 Echo Choke Adapter Black
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 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
Sierra Bullets 4540C 7mm 0.284 Caliber 140 Grain Tipped Boat
SilencerCo AC1278 ASR Black Nitride 9/16"x24 LH Threads 30 C
Sig Sauer W365XL-9-BXR3P-RXX P365 XL Romeo-X 9mm 3.7" Nitron
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...
Ready to Shop SI?
Choose SI for straightforward, well-engineered accessories that improve usability and durability without unnecessary complexity....
Browse All Products