my situation was different but it was a proof CF bbl and it was a 280ai it shot very well for a. Few months then all of a sudden groups were dancing all around not making any sense so I tried everything I was aware to fix bad groups and nothing helped so I sent it to my smith and we literally Tried his own load development double checked all his work and nothing worked SO I bought a new barrel ( not carbon wrapped) and my bad groups are just over an inch not the 3-4 inch I was getting with the CF. That being my smith has only seen this activity a few times with proof cf bbls. They start out great then they start doing odd groups for no reason and the common group I was getting was same hole same hole 3 inches away or one hole 3 inches away then back to the original hole and the misses we not consistent either they appeared all around the clock