Headspace is the difference between chamber and ammo.
As Jkob alluded, tolerance stacking can be a problem even if everything is
within spec. Ammo is a bottom of spec, chamber at top? Too much slop and problems.
I shoot a Rem 660 in 308, lost a casehead and had headspace checked 30 years ago.
The bolt will close on a no-go with a .010 chip on it.
Yep, she has headspace issues!
Went to neck sizing, then a FL die to bump the shoulder when they get snug.
Some of my LC match brass has been loaded 5 or 6 times, never separated another.
You rifle is probably fine.
Your loading process is definitely fine.
All that's really important.
