I'd say the crack is an indicator of where the recoil on the lug is significant. Anything can happen and I'm not surprised where it occurred. Fortunate to have it crack now rather than in early fall.
I should add:
At least ten years ago, I had a new Montana 300WSM go from a near MOA shooter to well over 2 inches at the second range session. Upon inspection, I discovered the lug split in two and it was something they handled quick enough.
Last edited by bigwhoop; 02/18/19.
