[Unclenick]

Higgite,

Military brass is even heavier. You'll find Lapua, Norma, Remington, and Federal are fairly close. The LC brass I have is mostly closer to 180 grains and the IMI brass I have is about 186 grains.

Winchester used to be about the weight of the other commercial cases, but around 1989 they signed on to develop brass for the 1992 Palma match, for which they wanted extra powder capacity, and wound up going to a semi-balloon head design that got some of the brass out. It proved popular, so later they switched over to that design for all their .308 brass. It saves them some raw material cost, so why not?

The result has been the .308 has more difference in capacity by brand (running from almost 55 to 59 grains water overflow capacity) than any other cartridge I am aware of except .300 Winchester Magnum. Nobody even makes military .300 WM brass, but it varies from about 88 to 96 grains water capacity, with Remington being heaviest and Norma being lightest, according to the QuickLOAD database.

When you get to .223 Rem/5.56 NATO and .30-06 brass, commercial and military cases currently have much less comparative volume difference except for some lots of Winchester being about 5% lighter in .30-06 than Lake City (but not all lots). Remington and Lake City are often the same. In .223, the military brass is often as light or lighter than many commercial cases, but the difference is small.