Thanks Steve, I had a good day.
I was also happy to see John S do well on his first ever benchrest shoot. After the 3rd target he had me tied.
Great job John S!
In the case of it being a left hand action the bolt is not closing enough, I would definitely start with a good cleaning of the action and bolt. Also check the firing pin and spring shroud for binding with the spring.
I would think .268 would be good or even .2675. This area is the spot that usually centers up the case in the chamber to hold the bullet in alignment with the bore.