barrel crown type

[isaaccarlson]

From a physics standpoint, 90* would be the most accurate, with angles moving away from this having more tendency to degrade accuracy due to any runout. .0001 runout won't matter with a 90* crown, but as the angle changes it will magnify the error, and by the time you get to this 60* that a few have mentioned, it will greatly exaggerate any error. The goal is to have gasses move away from the bullet in as direct a line as possible. A 60* angle does not do this and will push more gas around the base of the bullet, again affecting accuracy.

The crown is the infinitely thin edge where the muzzle and bore meet. That is what the crown is. The angle of that corner is what the crown angle is referring to. I prefer a full 11* crown, with the outer portion of the muzzle slightly rounded to increase toughness and reduce damage to the muzzle and any surface it may impact.

Yes, it needs to be very sharp. Chamfers on the crown are a no-no.

Smoother is better.

 

[JuddL]

I know several gunsmiths that chamfer the muzzle crown. It's recessed then a 45 to cut the sharp edge off.

I've left them sharp and chamfered with no noticeable difference in accuracy. Chamfered will make it harder to get nicked in a spot and that will for certain effect accuracy. I'm talking hunting guns more than a bench rest rifles.

 

[isaaccarlson]

And everyone is going to do it their way. That's how life works. I was just explaining the physics behind it...tendencies and such. Use what works.