Building A New Savage Bolt Action For Range And Accuracy. I have kicked the the 6.5 to the 6.8 around the forum, but now i'm leaning towards the .308. Did some research and reading on the ACC 300 Blackout today. I found 2 perfect barrels that will fit the Savage action I'll be using. One in .308 @ 26" with a varmint contour that is fluted and one in ACC 300 @ 26" with a bull contour. The ACC 300 looks to be a promising caliber in a AR platform as did the 6MM, but how will it fly in a heavy barrel bolt rifle