FC brass probably has some of the weakest primer pockets of any brass I’ve used. I’ve had factory FC 270 WSM brass that I reloaded and only got 2-3 firings on. I had two I couldn’t seat a primer in after firing it as factory ammo, the pockets were so loose. I have also used it in .308 Win, .300 WM and .223. I have a couple of .223 brass I only got 3-4 firings on, and some .308 that’s starting to loosen up after 3-4 firings. For some reason, my .300 WM brass is still good, with most on 4 firings.
