Barrel Crowning

[kieefer]

I found this subject interesting and thought I'd share it. I really don't know how common it is but the benefits make a lot of sense.

I'm considering this mod on a couple of hand guns even though it may be more applicable to rifles (?), any thoughts are welcome.

Crowning a rifle barrel, in simplest terms, is shaping the muzzle sothe rifling's edge is protected from impact. Most factory barrels havea round, convex-shaped crown from bore's edge to the barrel's

outsidediameter. That's easy to make and finish, plus looking rather pleasing.

The accuracy part of the crown means the land and groove part of thebarrel must let the bullet's base exit evenly all the way around. Whenthis happens, gas escapes uniformly and evenly around the bullet's base.If gas escapes unevenly (poor crown, even unsquare bullet bases), thepoint of greatest gas release will push the bullet in the oppositedirection and tilt it. Tilted bullets leaving the barrel just don'tshoot straight; how far they move sideways depends on their velocity,spin rate, and degree of tilt (or yaw, as it's sometimes called).

http://yarchive.net/gun/barrel/barrel_crowning.html

Cool little tool just for this purpose ;

http://youtu.be/b23lfzpZrJ4

[gregintenn]

Recrowning a barrel is beneficial when cutting one off, or when something has damaged the original crown, such as gravel in the floorboard of your truck scratching it, or dropping the gun on end, etc. A handgun or rifle will not shoot worth a whit without a good, consistant crown. The tool you are looking at isn't a magic wand, however. Recrowning an undamaged barrel shouldn't make much difference.