I have found that the 99's require a small base die inicially to bring the brass back to sammi spec,usually once you do this you can fire it in that chamber and just full length size it.Used brass could have been fired in a bigger chamber hence the no extract issue.You are on the correct track now and enjoy one of the best thought out rifles ever produced in the world.It was way ahead of its time.Its so good bill ruger collected them and copied the rotary mag for his rifles.