Military cases such as the .308 Winchester (7.62mm NATO) and .30-06 military brass have thicker case walls, and therefore less internal case capacity. It has been generally recommended that handloaders reduce all load charges by at least one grain when using .30 caliber military cases. In the .223 Remington (5.56mm NATO), the internal capacity of most military brass we have worked with has not measured significantly different from commercial cases. When using military cases, always check the capacity against the last lot of commercial brass you were using to avoid any potential problems, and adjust the load accordingly.
Is military brass interchangeable with commercial brass?
Sierra Bullets > FAQs > Is military brass interchangeable with commercial brass?