Depending on when your gun was made, its going to be 1:48" or 1:66" ROT. To figure it out for YOUR GUN, follow Zonie's advice. There is also an Article on the forum- look up on the Index page for the box marked " MEMBER RESOURCES", and then scroll down to "Articles, Charts, and Link". Click on Articles and you eventually get to a Table of Contents for about a dozen articles of interest. You will find the article on determining your guns ROT there.
There is No good reason why anyone should not know the ROT of his rifling. :thumbsup: :hatsoff: :hatsoff: