So you want to make 30BR brass quick? Have we got the mandrel for you.
A while back, while forming some 30BR brass for a customer's rifle we noticed that after necking 6mm up to 30cal the neck fit on the turning mandrel was a lot tighter than we wanted. Regardless of how many steps we took to get there we had to run the case necks over the final expander repeatedly to get the fit right. After that experience we decided to set out and make a mandrel with optimum taper and diameter to neck 6mm up to 30cal. in one step. After a lot of prototyping and split necks we've come up with what we think is the best way to expand the necks of 6BR Lapua brass and give you the best neck turning mandrel fit possible. Remember to always use plenty of lubricant when necking cases up.