IMR Enduron 8133 — New Slow-Burn-Rate Magnum Powder

IMR, a Hodgdon Powder Company brand, will soon release a new, slow-burn-rate magnum powder, IMR Enduron® 8133. This new powder is designed for large, magnum cartridges, such as .300 Win Magnum, .300 Remington Ultra Magnum, and 28 Nosler, among others. With the slowest burn rate among Enduron powders, 8133 has burn properties similar to Hodgdon Retumbo. The new Enduron 8133 powder will be available in 1-lb and 8-lb canisters starting in February 2018. Load Data for this new powder is already listed on the Hodgdon Reloading Data Center.

CLICK HERE for IMR Enduron 8133 Reloading Data »

IMR® Legendary Powders now offers five (5) Enduron powders: IMR 4166, IMR 4451, IMR 4955, IMR 7977, and IMR 8133. “It was always our intent to fill out the Enduron line with a magnum powder and we could not be happier with how 8133 performed in development and testing,” says Ron Reiber, Hodgdon ballistician. “This powder delivers the [slow burn rate] magnum-caliber reloaders require and adds all of the performance characteristics of the Enduron line of powders”. These qualities include temp stability, significantly reduced copper fouling, and optimal load density.

Modern Powder Technology for Enhanced Performance

Copper fouling reduction – these powders contain an additive that drastically reduces copper fouling in the gun barrel. Copper fouling should be minimal, allowing shooters to spend more time shooting and less time cleaning a rifle to retain accuracy.

Temperature change stability – the Enduron line is insensitive to temperature changes. Whether a rifle is sighted in during the heat of summer, hunted in a November snowstorm or hunting multiple locations with drastic temperature swings, point of impact with ammunition loaded with Enduron technology will be very consistent.

Optimal load density - Enduron powders provide optimal load density, assisting in maintaining low standard deviations in velocity and pressure, a key feature for top accuracy.

Environmentally friendly - Enduron technology is environmentally friendly, crafted using raw materials that are not harmful to the environment.

The Enduron Line-Up of Five Powders

IMR now offers FIVE Enduron powders that cover a broad range of burn rates. They are suitable for a wide variety of cartridges, from small varmint cartridges all the way up to the .338 Lapua Magnum.

IMR 4166 possesses the fastest burn rate in the Enduron lineup. It is the perfect burn speed for cartridges such as .308 Win, 7.62mm NATO, 22-250 Rem and 257 Roberts. A versatile, match-grade propellant, IMR 4166 is comparable to Hodgdon® Varget.

IMR 4451 is a mid-range burn speed powder, ideally suited for cartridges such as .270 Winchester, .30-06 and 300 Winchester Short Magnum. This powder is comparable to Hodgdon H4350.

IMR 4955 is a medium burn speed powder, falling in between IMR 4451 and IMR 7977 in burn speed. It provides top performance in big game cartridges such as 25-06, 280 Remington and 300 Winchester Magnum. This powder is comparable to Hodgdon H4831.

IMR 7977 has the second slowest burn rate among the Enduron Technology powders. It yields great performance in .300 Winchester Magnum, 7MM Remington Magnum, and .338 Lapua Magnum. IMR 7977 is comparable to Hodgdon H1000.

IMR 8133 is designed specifically for magnum calibers, such as .300 Remington Ultra Magnum, 28 Nosler, or the .264 Winchester Magnum, among many others. This new powder has the slowest burn rate among the Enduron powders and compares in burn rate to Hodgdon Retumbo.