I am new to the 6.5 CM and very excited to get started. I've done quite a bit of handloading on and off over the last several decades of other cartridges but this time around I decided to go with bushing dies vs standard FL & neck so I'm a newbie to bushing / tension adjustment. I hope I'm not complicating my standard procedures that commonly produce .5 MOA or better ammo with this bushing technique.
I'm trying to get a better understanding of how tight to make them. Breaking her in with Hornady but also have 100 Lapua on hand. Hornady Match& American Whitetail that I'll use for barrel break in all measure .291 at the neck unfired. Lapua out of the box and once fired Hdy all measure .015 neck thickness. So that gets to .294 with "no" tension. .291 is a .003 squeeze, .288 is .006 squeeze which seems like a lot. I don't even know how one gets down to that dimension starting with .264 + .030. What's happening here, is the bullet getting the brass squished into it? From what I've read, .001 -.002 is what to shoot for so I bought .289, ,291 and .292 bushings.
Also, the RCBS Gold Medal bushing dies I bought have an expander ball which I don't understand because I thought that defeats the purpose of the bushing approach.
Please help me understand.
Thanks in advance.