It may have a recess Slice into the center area of the crown (see illustration). This is often common on our centerfire rifles. It pretty very well may be that with some experimentation that an RoT could be formulated that says anything like: Recess stage depth equivalent to or below https://pin-and-weld36814.worldblogged.com/33865275/not-known-factual-statements-about-barrel-crown