I'm loading 42 gr of H4350. Seating 2.215 at the ogive which is about .050 off the lands.
15 rounds at 100 yds from a bipod and rear bag.
5 rounds at 500. Bipod and bag.
First of all, power down those loads. Looks way too hot.
Look for a burr or foreign object scratching up your cases. See if it happens when you single feed. That will rule out some areas to look.
Shot this target at the farm today. 100 yds from bipod and rear bag. Rifle is Rem 700 w Bartlein barrel chambered in 223 sitting in a Manner T6A with mini chassis. Rifle was put together by Keith Kilby at Wyoming Armory. I'm shooting 80 gr SMK with 24.5 gr of Varget.