I had just the FL dies and used them on once fired brass. Probably an average of three out of every magazine wouldn't chamber so I bought a SB sizing die and it fixed the chambering problem. Same thing happened in my LAR308 but I got two reloads out of the brass before it wouldn't chamber.
If I had it to do over again, I would still do it the same way - use what I already have until it doesn't work then buy the SB, unless you're using it in competition then you really can't take that chance.
Does anybody know if I can run loaded rounds through the SB die so I don't have to pull the ones that won't chamber?