IMR Load Data

The IMR (Improved Military Rifle) brand traces its origins to the early 19th century under the DuPont Corporation, a name synonymous with the development of high-performance gunpowder. E.I. du Pont, having arrived in America in 1800, established a gunpowder manufacturing facility by 1802 along the Brandywine River in Wilmington, Delaware. This site eventually evolved into the modern GOEX brand, now known for producing black powder.

IMR powder brand logo

DuPont quickly became a major supplier of military propellants, first seeing combat use in 1805 by U.S. naval forces during engagements off the coast of Algiers. By the time of World War I, DuPont was producing over 80% of the smokeless powder used by Allied forces. During World War II, demand for propellants soared—leading to the production of an astonishing 2.5 billion pounds of smokeless powder for Allied forces, reflecting the scale and importance of DuPont's role in global military supply.

The IMR brand itself was launched in the 1930s as part of DuPont’s push to provide more refined and consistent rifle powders for both military and civilian applications. Among the first powders introduced were IMR3031 (1934), IMR4064 (1935), and IMR4350 (1940)—formulations that remain staples in the handloading community to this day. IMR powders quickly earned a reputation for delivering the performance and consistency necessary to optimize rifle ballistics, becoming a go-to choice for generations of precision shooters and reloaders.

In 2003, the Hodgdon Powder Company acquired the IMR brand, uniting it with other prominent names such as Hodgdon, Winchester, and GOEX under one umbrella. Today, the IMR product line continues to offer a wide selection of powders engineered for handloaders, maintaining its status as a legendary name in reloading history.

We have load data for the following IMR powders:

IMR 8133 Enduron powder container

IMR 8133 Enduron

IMR Enduron 8133 is the slowest burn rate in the Enduron family. Loading density is perfect for magnums, contributing to superb uniformity. This is a… Read more about 8133 Enduron

Burn rate: 0.2Rifle calibers

IMR 7977 Enduron powder container

IMR 7977 Enduron

IMR Enduron 7977 is a slower burn rate in the Enduron family. Loading density is perfect for magnums, contributing to superb uniformity. This is a… Read more about 7977 Enduron

Burn rate: 0.6Rifle calibers

IMR 7828 SSC powder container

IMR 7828 SSC

IMR 7828 SSC is a magnum rifle powder with exactly the same burn rate as standard IMR 7828 and uses the same data. However, due to the super short… Read more about 7828 SSC

Burn rate: 1.2Rifle calibers

IMR 4350 powder container

IMR 4350

IMR 4350 is a medium- to slow-burn rate propellant and is the number one choice for the new short magnums, both Remington and Winchester versions… Read more about 4350

Burn rate: 1.5Rifle calibers

IMR 4831 powder container

IMR 4831

IMR 4831 has a slightly slower burn rate speed than IMR 4350. It provides top velocities and performance with heavier bullets in medium-sized magnums.

Burn rate: 1.8Rifle calibers

IMR 4955 Enduron powder container

IMR 4955 Enduron

IMR Enduron 4955 is a versatile, match-grade propellant with a mid-range burn speed that is in between IMR4451 and IMR7977. It is an extruded powder… Read more about 4955 Enduron

Burn rate: 2Rifle calibers

IMR 4451 Enduron powder container

IMR 4451 Enduron

IMR Enduron 4451 is a versatile, match-grade propellant with a mid-range burn speed in the Enduron line. It is an extruded powder and is perfect for… Read more about 4451 Enduron

Burn rate: 2.4Rifle calibers

IMR 4064 powder container

IMR 4064

IMR 4064 is a medium-range burn speed powder and is one of the most versatile propellant in the IMR line, used for 223 Remington, 22-250 Remington… Read more about 4064

Burn rate: 4Rifle calibers

IMR 4166 Enduron powder container

IMR 4166 Enduron

IMR Enduron 4166 is a versatile, match-grade propellant, with the fastest burn rate in the Enduron line. It is an extruded powder with a perfect burn… Read more about 4166 Enduron

Burn rate: 4.2Rifle calibers

IMR 4895 powder container

IMR 4895

Originally a military powder featured in the 30-06, IMR 4895 is extremely versatile as a medium burn speed propellant. From the 17 Remington to the… Read more about 4895

Burn rate: 4.4Rifle calibers

IMR 8208 XBR powder container

IMR 8208 XBR

IMR 8208 XBR is an accurate-metering, super short-grained extruded rifle powder was designed expressly for match, varmint, and AR sniper cartridges… Read more about 8208 XBR

Burn rate: 4.8Rifle calibers

IMR 3031 powder container

IMR 3031

A medium burn speed propellant with many uses, IMR 3031 has long been a favorite of 308 Match shooters using 168-grain match bullets. It is equally… Read more about 3031

Burn rate: 5.2Rifle calibers

IMR 4198 powder container

IMR 4198

This fast-burning rifle powder gives outstanding performance in cartridges like the 222 Remington, 221 Fireball, 45-70, and 450 Marlin. It is also… Read more about 4198

Burn rate: 5.6Rifle calibers

IMR 4227 powder container

IMR 4227

IMR 4227 is a medium burn speed, magnum pistol propellant. If a pistol says Magnum, IMR 4227 is the choice for true magnum velocities and… Read more about 4227

Burn rate: 6Rifle calibersHandgun calibersSubsonic

Burn rate is a relative scale: lower values burn slower, higher values burn faster.

Sample IMR load data

A cross-section of calculated IMR loads from our database, covering different calibers and bullets. Open a powder or caliber to see the full load tables.

Last updated: October 27, 2026

CaliberBulletPowderCharge (gr)Max. pressure (psi)Muzzle velocity (fps)
.308 Win..308 | 190gr | Hornady Sub-XIMR 422731.259,8572,352
6.5 Creedmoor.264 | 147gr | Hornady ELD MatchIMR 483141.357,9862,667
.223 Rem..224 | 55gr | Hornady Traditional/FMJIMR 422720.255,2593,140
7 mm PRC.284 | 175gr | Hornady ELD-XIMR 7828 SSC66.561,3372,923
6.5 PRC.264 | 143gr | Hornady ELD-XIMR 435051.761,4672,861
6 mm GT.243 | 105gr | Berger Hybrid TargetIMR 8208 XBRAvailable with access license61,0902,851
.243 Win..243 | 100gr | Sierra SBT GameKingIMR 4895Available with access license56,7392,940
.30-06 Spring..308 | 168gr | Barnes TTSX BTIMR 8208 XBRAvailable with access license58,4502,762
.22 Creedmoor.224 | 85.5gr | Berger Long Range Hybrid TargetIMR 4831Available with access license64,4113,192
.338 ARC.338 | 300gr | MAKER .338 ARC/Spectre Expanding SubsonicIMR 4198Available with access license32,7931,194
.222 Rem..224 | 55gr | Sierra SBT GameKingIMR 8208 XBRAvailable with access license44,4252,992
.300 Win. Mag..308 | 178gr | Hornady ELD-XIMR 4831Available with access license60,2202,940
7 mm Rem. Mag..284 | 168gr | Berger VLD HuntingIMR 4350Available with access license61,7862,851
.270 Win..277 | 145gr | Hornady ELD-XIMR 4064Available with access license60,8432,848
6.8 Western.277 | 155gr | Barnes LRX BTIMR 4895Available with access license64,9052,923
.300 Norma Mag..308 | 220gr | Berger Long Range Hybrid TargetIMR 8133 EnduronAvailable with access license49,1972,713
.257 Roberts.257 | 117gr | Hornady SSTIMR 4350Available with access license51,2272,822
.300 WSM.308 | 190gr | Nosler AccuBond Long RangeIMR 4831Available with access license61,8732,838

Personalized Load Calculator

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Popular load data

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Frequently asked questions about IMR powders

This page lists 14 IMR powders with load data: IMR 8133 Enduron, IMR 7977 Enduron, IMR 7828 SSC, IMR 4350, IMR 4831, IMR 4955 Enduron, IMR 4451 Enduron, IMR 4064, IMR 4166 Enduron, IMR 4895, IMR 8208 XBR, IMR 3031, IMR 4198, IMR 4227.

IMR 8133 Enduron has the slowest burn rate at 0.2, and IMR 4227 the fastest at 6. Lower values burn slower.

We hold load data using IMR powders for 369 calibers. The most common ones are .300 Win. Mag., .300 Weath. Mag., .300 H&H Mag., .308 Norma Mag., .308 Win., .30-06 Spring., .300 Blaser Mag., .300 Rem. Ultra Mag..

Yes. IMR 4227 is flagged as suitable for subsonic loads.

Currently 301,004 load records using IMR powders, spread across 369 calibers.

The values are calculated with an inner-ballistics engine across the full charge range and cross-checked against IMR product data. They are reference data for experienced handloaders: always start at the minimum charge, work up carefully and cross-check against current published data before firing.