At .454", the inside diameter of your bolt face could be a little over-sized. Having never owned or even handled a Ruger American in 6.5Grendel/6 ARC, I can't say for sure it's an issue. My 6.5 Grendel Howa mini bolt face is right on .450" & it chambers & extracts as slick as can be. I did change my polymer trigger guard for Jefferson Outdoors hinged floorplate bottom metal which was a major improvement in round cycling.
The trick is growing up without growing old. -- Casey Stengal