02-13-2014, 11:59 PM
JASmith Wrote:The ring you observed is troubling in that there is no feature described in the SAAMI drawing that would evoke a feature like that. Furthermore, I am told that the way to fix a tight chamber is to run a finishing reamer through it. That operation should not produce the ring you describe.Yes there is.
There will be a short portion of the SAAMI Grendel throat just in front of the 45 degree cone that does not have lands. That is the portion that starts larger than the bullet and groove (.264)and tapers smaller at .5 degree. Even though it is part of the compound throat there is a small section of freebore(land-less bore) until the .5 degree taper becomes smaller than .264 and the lands start.