Thread: Expander mandrel use ? Is it worth it ?

I have heard that about bushings not being as accurate as the mandrel, but from what I've been seeing on my lots of cases is that the case neck thickness variation produced more of an error than either method. The mandrel had about half the neck thickness error than the bushing by itself - which makes a lot of sense. Either way, the case neck thickness error in the large proportion of brands of brass is less than 2 thou runout from what I have seen and brands like Lapua and Norma are generally well under that. If it's a standard hunting rifle there's more error in the thing than a thou or so of runout (but it probably makes you feel better knowing it's not there).