Re: Barrel crown
My preference is a 11o crown for several reasons.
1 - It does a good job protecting the muzzle bore if it is properly cut (At least 75% of the diameter of the barrel).
It also is more durable than a recess crown because it has a 101 degree exit angle to the bore and the recess crown has a 90 degree angle at the muzzle bore making the 11 degree crown more durable.
Also In my opinion "All" crowns should be cut in a Lathe with the barrel perfectly center on the bore and cut with a single point tool.
Just my opinion