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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 (2,385)
SilencerCo ASR Flash Hider 7.62mm Steel 1-2"-28 tpi Compatible with ...
SilencerCo ASR 3-Port Muzzle Brake 7.62mm Black
SilencerCo AC1278 ASR Black Nitride 9/16"x24 LH Threads 30 Cal
SilencerCo ASR 762 Muzzle Brake 9/16X24 AC1276
SilencerCo AC1245 Echo Choke Adapter Browning Invector Improved Cylinder
SilencerCo AC1217 Echo Choke Adapter Beretta Optima Improved Cylinder
SilencerCo AC875 Rimfire Adapter M&P 22 Compact 1-2x28 Steel
SilencerCo AC859 9mm 5" Threaded Barrel Black Nitride for SIG P226
SilencerCo AC860 Threaded Barrel 9mm Luger 5.31 in Black Nitride
Silencer Co AC862 Threaded Barrel 1/2x28 for Glock 19, 416R Stainless Steel
SilencerCo Threaded Barrel for Glock 17 9mm Luger 1/2x28 Black
SilencerCo AC864 9mm Threaded Barrel 5" Black Nitride for Glock 17 Gen 1-4
SilencerCo Salvo Suppressor Choke Adapter - 12 Gauge, Matte Black
SilencerCo SC Echo Choke Adapter for Beretta/Benelli Mobil Shotguns
SilencerCo SC Echo Choke Adapter for Benelli Crio
SilencerCo AC872 Salvo 12 Mossberg 500 Choke Mount Adapter Black
SilencerCo AC874 Echo Choke Adapter Remington Improved Cylinder
SilencerCo AC837 Alpha Direct Thread Mount Fits M18X1 Matte Black
SilencerCo Charlie ASR Mount - Quick Attach/Detach System for Suppressors
SilencerCo ASR Mount for Omega 300/Harvester Big Bore 338/Hybrid Suppressors and ASR Compatible Muzzle Devices Matte Black
SilencerCo AC858 ASR Muzzle Brake Black Steel with 3/4"-24 tpi Threads
SilencerCo Hybrid ASR Muzzle Brake 5/8x24 .338 Caliber Black
SilencerCo AC233 ASR Flash Hider 30Cal M15x1 Nitride Black
SilencerCo AC735 Harvester Big Bore Thread Mount M18 x 1.5 Black
SilencerCo Piston 13.5x1 LHM XL Stainless Steel Natural Finish
Silencer Co Bravo Direct Thread Mount, 5/8x24, Black
SilencerCo AC668 Bravo Direct Thread Mount Fits 3/4"x24 Matte Black
Silencer Co Alpha Direct Thread Mount, 5/8 x 34, Solid Steel, Black
Silencerco SPECWAR 7.62 Muzzle Brake Mount AC591
SilencerCo ASR Flash Hider 5/8x24 .30 Caliber Black
Silencer Co Thread Spacer for .22 LR Rifles
SilencerCo Hybrid ASR Muzzle Brake 1/2x28 .223 Caliber Black
SilencerCo ASR Flash Hider 1/2x28 .223 Caliber Black
SILENCERCO Osprey/Octane O-Ring Booster Pack(AC88)
SilencerCo Piston 1/2x28 Xtra Long Stainless
SilencerCo Piston 1/2x36 Stainless Steel
SilencerCo 17-4 Stainless Steel Piston for .40 S&W Handguns
SilencerCo Osprey/Octane Piston 5/8x24 Stainless Steel
SilencerCo Stainless Steel Piston for .45 ACP Handguns M16x1 RH
SilencerCo Osprey/Octane Piston - Stainless Steel, Metric 16x1 LH (AC28)
SilencerCo Stainless Steel Piston for Omega K Hybrid Osprey Octane Series
SilencerCo Piston 13.5M x 1LH Stainless Steel
SilencerCo Osprey/Octane Piston .578x28 Stainless Steel
SilencerCo Delta Thread Protector 1/2-28 AC6 Stainless Black
SilencerCo Osprey/Octane Fixed Barrel Spacer 17-4 Stainless
Silencerco 22 Adapter P-22 With Thread Protector Black Barrel Ac5
FN Five-seveN M10x1 to 1/2x28 Delta Adapter Suppressor-Ready
SilencerCo AC3 Delta Adapter 1/2x28 Threaded
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...
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Choose SI for straightforward, well-engineered accessories that improve usability and durability without unnecessary complexity....
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