Overview: Doing load development for Seekins Havak Pro Hunter PH2 in 300WM, brand new with maybe 60 rounds of factory ammo through it. Rifle owner gave me the once shot brass after he zeroed it. I noticed the once shot brass was quite a bit more difficult to resize than I am use to, to the point were I was getting small brass shavings near the belt. Never had this issue with my 300WM once shot brass.
Range: Did a work up of H4831SC from 68.7 to 70.5 with Nosler 200AB. At 68.9 had partial case head separation and a barely flattened primer @ 2752 fps. I immediately stopped there. I shot a factory Hornady ELD-X 200gr just to check since I've never shot this rifle before. Primer was extremely flat and a nice shiny ring above the belt. This leads me to believe the headspace is off by quite a bit, but wanted to double check with people more experienced than I.
Measurements:
Hornady ELD-X 200gr unfired factory round
Datam at shoulder: 2.256
Diameter just above belt: 0.506
Once shot
Datam at shoulder: 2.274
Diameter just above belt: 0.516
I attached the pictures of the once fired FACTORY round.
Any thoughts and advice? I appreciate your time.
Range: Did a work up of H4831SC from 68.7 to 70.5 with Nosler 200AB. At 68.9 had partial case head separation and a barely flattened primer @ 2752 fps. I immediately stopped there. I shot a factory Hornady ELD-X 200gr just to check since I've never shot this rifle before. Primer was extremely flat and a nice shiny ring above the belt. This leads me to believe the headspace is off by quite a bit, but wanted to double check with people more experienced than I.
Measurements:
Hornady ELD-X 200gr unfired factory round
Datam at shoulder: 2.256
Diameter just above belt: 0.506
Once shot
Datam at shoulder: 2.274
Diameter just above belt: 0.516
I attached the pictures of the once fired FACTORY round.
Any thoughts and advice? I appreciate your time.