tight throat?

Have you ever come across this? I have a Savage 12LRP 6.5 Creedmoor. My 6.5 loves Winchester 140 grain BTHP Match (one hole groups). I have tried many others but my issue is this for example it chambers Hornady 129 grain SST but does not chamber Hornady 120 grain ELD Match. It chambers Atomic (Sierra 142 grain Match King) but does not chamber Sierra 140 grain Match King (reloads). Bullets have "scuff" marks on largest O.D. like the chamber throat is tight, no rifling marks on the bullets just "scuff" marks pretty much all around the bullet. I have measured the bullets and the difference would have to be .0001 or so. In 50+ years of shooting I have never come across this, especially a new rifle not chambering factory rounds. Any ideas?