Originally Posted by robocop10mm
FC is Federal Cartridge. The FC headstamp is used on some of the "mil spec" or LE ammo. The FC ammo "may" have been manufatured at the Lake City plant that Federal (ATK) runs for DoD. The brass "may" be slightly different than the Fed or Federal stamped brass. It may be made on different machines and/or made of a slightly different alloy.
The best bet is to weigh the cases and sort by weight. Weight will depend mostly on thickness of the brass. Thickness will affect volume. Volume will affect pressure so powder charges must be adjusted to compensate.
WTS, Federal (Fed, FC) brass is my favorite. It tends to run a bit harder than some other brass. Because of the hardness it is "tougher" but may have a slightly shorter life span. You may not get as many loadings out of it. I generally lose the brass before I get any splits.
Thanks for the detailed response.
I was thought the diff. between FC 223 Rem & FC 08 was commercial and military, respectively.
Would weighing the cases be that crucial if I am not loading to max or near max loads?
I have been sorting them by year as they come out of the 1st tumble.