My Sierra reloading manual says the loaded cartridge has a neck diameter of 343". My loaded PMC cart. has a neck diameter of 335.5". My fired brass is 346". I know it must spring back from the full diameter of the chamber and that amt. is known.....but not by me. What is the neck size my chamber is reamed to?

I am told that my neck diameter for a no turn neck should be .002" inches larger than the chamber neck for a bolt action and .003 for a auto loader. my arithmetic says that the neck should be reamed to .3355 plus .002......or, 338 to round it out. Correct?

Won't this current condition overwork the brass in the neck?

Thanks for the advice,


John