[Ray Meketa]

Virtually all US military ammunition has some sort of primer seal. It has been so since the beginning of the last century. As a general rule, the color itself does not mean anything but there are many examples where the color indicates certain loads. Serious collectors know what the colors are and what they mean.

Foreign military ammunition is another thing altogether. Primer colors mean a lot of things and many use a color bullet seal to further identify cartridges.

Ray