Powder Lot Variations: A Case Study with H4831 - Hodgdon Extreme
Abstract
Small arms propellant manufacturer Hodgdon claims that rifle powders in its Extreme line have small velocity variations with both temperature changes and lot number. This paper reports on the variations in average velocity for six different lots of Hodgdon Extreme H4831 tested in .25-06 and .300 Winchester Magnum loads. Compared to the lot with the slowest average velocity, the other five lots of powder had higher average velocities ranging from 11.9 ft/s faster up to 111.9 ft/s faster in the .25-06 and from 13.6 ft/s faster to 111.1 ft/s in the .300 Win Mag. The mean velocity differences between lots are highly correlated between the two cartridges with a correlation coefficient of 0.96. This high correlation supports the idea that the experimental results reported here depend much more strongly on differences in the lots of powder rather than other details of the experiment such as the choice of primers, brass, bullets, and specifications of the rifle bore. The lot to lot variations in velocity seem higher than one might expect from Hodgdon's marketing claims.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 30, 2012
- Accession Number
- ADA572333
Entities
People
- Elya R. Courtney
- Michael W. Courtney
Organizations
- United States Air Force Academy