Product Overview and Introduction

Master extreme precision, eliminate copper fouling, and enjoy exceptional temperature stability across a wide variety of popular rifle calibers with IMR 4166 Smokeless Powder with Enduron Technology (1 lb). Part of IMR’s revolutionary Enduron technology line, IMR 4166 is an advanced extruded (stick) propellant engineered with a built-in copper-fouling eliminator. This innovative additive helps prevent copper buildup in your barrel, drastically reducing cleaning time and preserving match-grade accuracy over long strings of fire.

Whether you are handloading precision match rounds for the .308 Winchester, crafting varmint loads for the .223 Remington, developing tactical ammunition for the 5.56 NATO, or reloading for classic cartridges like the .30-06 Springfield and .250 Savage, IMR 4166 delivers incredible consistency, modern eco-friendly performance, and the convenient sizing of a 1-pound container.

Revolutionary Enduron Technology and Precision

Built using advanced chemical engineering, IMR 4166 offers distinct advantages for precision handloaders:

• Copper-Fouling Eraser: Integrated additive significantly reduces copper accumulation in the barrel bore, making post-range cleanups faster and maintaining tight group sizes.

• Insensitive to Temperature Extremes: Formulated to maintain consistent velocity and pressure stability regardless of whether you are shooting in freezing winter weather or scorching summer heat.

• Extruded Stick Uniformity: Precision-cut grains meter smoothly through powder measures and drop tubes for consistent charge weights and ultra-low velocity standard deviations.

• Clean-Burning Formulation: Minimizes carbon fouling to keep your firearm running cleaner throughout extended shooting sessions.

The Professional Choice for Modern Precision Rifle Reloading

When your reloading bench demands a high-tech, barrel-friendly propellant in a convenient 1-pound container that delivers zero temperature sensitivity and top-tier accuracy in calibers like .308 Winchester and .223 Remington, IMR 4166 Smokeless Powder stands out as an elite modern solution.

Key Features and Benefits

• Enduron Benefits: Built-in copper fouling deterrent extends barrel accuracy intervals between cleanings.

• Caliber Versatility: Exceptional performance in .308 Winchester, .223 Remington, .30-06 Springfield, .243 Winchester, and 5.56 NATO.

• Eco-Friendly Formulation: Non-toxic additives aligned with modern green chemistry standards without sacrificing ballistic performance.

• Available Packaging: Convenient 1-pound canister, ideal for recipe development and standard stock.

Specifications

• Product Type: Smokeless Powder (Extruded / Stick with Enduron Technology)

• Brand: IMR

• Powder Family: IMR 4166

• Burning Rate: Medium (comparable to Varget / IMR 4064)

• Primary Applications: .308 Winchester, .223 Remington, .30-06 Springfield, 5.56 NATO, and Medium Rifle Cartridges

• Packaging Size: 1 lb Canister

• Storage Requirement: Store in a cool, dry place away from heat, sparks, open flames, and direct sunlight