308 Military Brass

buddyb

Loaded some 308s,some in military brass and some in commercial brass.The military brass has flattened primers after firing but the commercial does not.Too hot?

richbug

Military brass generally has a lower case capacity, and will show pressure sooner.

nononsense

buddyb,

If every other variable is the same for both sets of cases then I would say that the military cases had less capacity and therefore the pressure was higher, flattening the primers. That's the usual reason because the military cases are thicker to begin with. If you switched variables between sets of commercial and military cases then you have to tell us what you did in more detail.

There is also the possibility of other reasons that have to do with chamber wall grip and a couple of other factors but it is most likely that the military cases have a smaller capacity.

Best.

B17-P51

Fill the brass with sand or salt or sugar in the same manner for each case and weigh the contents of each case filled to the rim. You will probably find the military brass holds less than the commercial.

Mobuck

Every reloading manual I have says military brass is thicker and requires a lower powder charge than commercial brass. No kidding, I believe them without checking for myself.

11b6r

Bear in mind that the miltary brass is not .308- it is 7.62 NATO- and while they are real close, they are not identical. Yep, thicker case, less volume, pressure goes up. 7.62 NATO is loaded to (I think) a max of 50K CUP, .308 is max 55,000 CUP.

JustC

military brass has lesser volume,..hence the pressure spike