As much as I like the group, at times its really annoying when people ignore what is being presented.
Please read down far enough into this post where it shows a 5 grove barrel and the issue in measuring. It also clearly explains form the start there is an issue.
http://castboolits.gunloads.com/show...oove-bore-slug
Sometimes it just gets to the point I don't care if what is presented is ignored, its as much about getting people to pay attention as helping (more)