very nice.did you have same problem with shorter o.a.l?
Yes. The case head separation actually happened when I was seated about .050 off the lands. But I don't think seating depth is playing a role here. My understanding is it's a function of repeated expansion and resizing cycles with a chamber that is set up beyond spec, coupled with resizing the brass back 0.008 each time.
It sounds like I need to take the rifle back to the smith and have him verify that the chamber is set for proper headspace.
yes i agree with having it verified,Reason i ask is if it shoots as well as you describe seems to be a very well built rifle.A loose chamber most likely will not hold 1/2 moa.Have you tried farther out like factory around .150 from lands and see how well that magnum shoots and if it still causes the separation?