I’m looking to expand the necks on some new lapua brass in 6.5CM so I can run them thru my .291 bushing to get the correct tension. I’m confused on exactly what I need . I was looking at the mandrels but from what I understand, those are just to manipulate the neck tension from the inside. I talked to Pat Regine at PMA and he can make me a custom mandrel but will take a few weeks and I need something a little sooner than that. Any suggestion?
Expanding new brass necks
- Thread starter Duramax6
- Start date
Using Hornady brass my 6.5cm loaded has a .291 neck so I use a .288 redding bushing, which actually is slightly smaller, when sizing and then expand with a Sinclair turning mandrel which is 2 thou under and actually measures .2615
I just started loading for my bolt gun in 6.5. Before then it was just for my gas gun. The .291 worked fine on some hornady brass, for the exception of a few. They were loose due to the run out within the necks. I went back to some lapua and looking for something to slightly open the necks to what you would get after a fired case. Didn’t know if they made a slightly larger expanding ball or something
Neck size below target neck diameter without expander ball then Sinclair expander mandrel out for neck tension
Exactly what Keith stone said. If done this way you will push imperfections to outside of necks and if you do it with bushing last you push those same imperfections into the inside of the neck where they will create inconsistencies with your bullet
