I recently put a new barrel on my 300 win mag and took it to the range. While there I fired 8 shots and on the 8th shot I had full case head separation. I took it home assuming my load was bad or something. Once home I checked the headspace again with forster and ptg gauges and went out and got a box of factory ammo to try that, well today I took it back out and it made it 4 shots with perfect brass and no pressure signs and the 5th one split. Chamber is clean and polished the bore is smooth and pretty. Anyone have any ideas why it would do this? I have 2 others I put together the same way and had no issues.


Edit: I also tried changing the bolt face and resetting the headspace but... same story