Thread: Fireform brass for subsonics .308?

Use brass fired in your dhamber and just neck size it, It will be headspaced for that chamber you will only need to bump the shoulder or full length size occasionally
Sub loads do not have enough pressure to form the case to the chamber and can actually cause headspace problems they have been known to shrink after a few firings
as they work harden and don't expand fully letting the high pressure gas back in to the chamber, If you get sooty shoulders it is the sign the pressure is leaking
back into the chamber, up the powder charge or go to a faster powder.