IMR 4831 Reloading Data

IMR 4831 is a slow-burning extruded rifle powder designed to provide top performance in overbored magnums and standard centerfire cartridges. This article contains published IMR 4831 reloading data for multiple cartridges to help you determine the appropriate powder charge for your application. Keep in mind that exact data depends heavily on the specific cartridge, bullet weight, components, and the original publishing source.

IMR 4831 Reloading Data

Cartridge	Bullet Weight (Grs.)	Min Charge (gr)	Max Charge (gr)	Max Velocity (fps)
243 Winchester	100	40.0	44.0	2,900
25-06 Remington	100	49.0	54.0	3,200
25-06 Remington	115	47.0	51.5	3,000
6.5x55mm Swedish	140	41.5	45.5	2,600
270 Winchester	130	52.0	57.0	3,050
270 Winchester	150	49.5	54.5	2,850
280 Remington	140	51.0	56.5	2,950
7mm Remington Mag	150	58.0	63.5	3,000
7mm Remington Mag	160	56.0	61.5	2,850
30-06 Springfield	165	54.0	59.0	2,800
30-06 Springfield	180	53.0	57.5	2,700
300 Winchester Mag	180	68.0	73.0	2,950
300 Winchester Mag	200	65.0	70.0	2,800
338 Winchester Mag	225	66.0	71.0	2,750
338 Winchester Mag	250	63.0	68.0	2,600

Explanation Of The Data

The supplied IMR 4831 reloading data covers a wide spectrum of popular centerfire rifle cartridges, highlighting the suitability of this powder for medium to large capacity cases. The table demonstrates how powder charge requirements and expected velocities shift depending on bullet weight and case volume.

270 Winchester

For the 270 Winchester, the table provides IMR 4831 load data for 130 grain and 150 grain bullets. The 130 grain bullet starts at a minimum charge of 52.0 grains and reaches a maximum of 57.0 grains for a top velocity of 3,050 fps. When moving to the heavier 150 grain bullet, the starting load drops to 49.5 grains, and the maximum charge is reduced to 54.5 grains, yielding a lower maximum velocity of 2,850 fps.

30-06 Springfield

The 30-06 Springfield data illustrates IMR 4831 performance with mid-to-heavy bullets. For a 165 grain bullet, charges range from 54.0 grains up to 59.0 grains, pushing the projectile to 2,800 fps. Using a heavier 180 grain bullet requires a smaller charge window of 53.0 to 57.5 grains, resulting in a maximum velocity of 2,700 fps to keep chamber pressure at a safe level.

7mm Remington Mag and 300 Winchester Mag

IMR 4831 excels in belted magnums. In the 7mm Remington Mag, a 150 grain bullet requires 58.0 to 63.5 grains to hit 3,000 fps. For the 300 Winchester Mag pushing a 180 grain bullet, the large case capacity dictates much higher charges of 68.0 to 73.0 grains, reaching up to 2,950 fps. As bullet weight increases within either caliber, powder charges and velocities decrease accordingly.

Understanding IMR 4831 Load Data

A starting load is the absolute minimum powder charge recommended by the manufacturer to safely ignite and propel the bullet out of the barrel. The maximum published load is the highest tested powder charge that remains within established SAAMI pressure limits. Velocity measures the speed of the bullet at the muzzle in feet per second (fps). Pressure data, when available, indicates the internal chamber pressure generated upon firing. Bullet weight and barrel length are critical factors; heavier bullets mandate smaller powder charges to prevent pressure spikes, while longer test barrels generally produce higher velocities. Cartridge overall length also dictates case volume and pressure. Load data differs between cartridges because each has a unique case capacity, bullet diameter, and operational pressure threshold.

Manufacturer Data vs Provided Data

The supplied table aligns closely with legacy published information found in older manuals from bullet manufacturers like Sierra and Hornady, as well as the Hodgdon Reloading Data Center. For example, the 270 Winchester 130 grain data (52.0 to 57.0 grains) perfectly matches historical Sierra data for IMR 4831. Current manufacturer data may show slight deviations from this chart due to modern pressure testing methods, different primer types, specific bullet bearing surfaces, or varying test barrel lengths. The provided table appears to be an aggregate of verified historical data points, but reloaders should always cross-reference with the most recent printed manual or online manufacturer resource.

IMR 4831 Safety

Reloading data is component specific. You must never substitute bullets, primers, or brass brands without consulting verified published data, because small changes can significantly alter chamber pressure. Starting and maximum loads must not be confused; you should always begin at the minimum listed charge and work up in small increments. Data for one cartridge cannot be transferred to another under any circumstances. Always follow published manufacturer data exactly, and do not attempt to create, optimize, or modify a load beyond these safe limits.

FAQs

What is IMR 4831 reloading data?

It is the tested and published specifications for loading IMR 4831 powder into specific rifle cartridges, providing safe minimum and maximum powder charges along with expected velocities.

What cartridges use IMR 4831 powder?

IMR 4831 powder is heavily used in overbored cartridges and magnums, such as the 270 Winchester, 25-06 Remington, 300 Winchester Mag, and 7mm Remington Mag.