I had a fellow size my 24 ga brass I previously shortened to 2 " and annealed in C+H dies. They didn't chamber in my gun....I know specs are all over the map. Left a couple cases with another fellow who has RCBS dies and Bingo they fit. Here's the issue, I have no projectiles other than some .592 diameter solid based conicals at 448gr. Too big as the FL sizer necked the brass to between .571-.573 " inside diameter. Can these be fireformed without projectile and if so with what? I have FG ,FFG + Unique on hand. Dacron or corn meal ? I hear contradicting stories of chamber ringing. Can a Parifin wax plug be used?