Crowning

[hammer111]

Would a gun that doesn't have a crowned barrel benefit from having a crown machined on the barrel.

Are crowns only for bolt action rifles or can a semi auto have one too.

 

[Gene]

Any rifle can have a crown. They are intended to protect the end of the muzzle from damage. Some shoot good with a flat finish.

 

[hammer111]

So crowns have nothing to with accuracy or not that much as you would think ?

 

[Barrelnut]

Hammer, here's an interesting LRH article on crowns.

The Over-Rated Crown

 

[hammer111]

Thanks

 

[J E Custom]

So crowns have nothing to with accuracy or not that much as you would think ?

This has long been a controversial subject and will probably continue.

My opinion is that A "GOOD" Crown is essential for best accuracy.

The intent of crowning is to create a perfect exit for the bullet so the gases are released uniformly
preventing any possibility of uneven discharge of the pressure behind the bullet. This could cause the bullet to yaw, hurting accuracy.

You will never see a bench rest shooter with a hacked off barrel, and even though it may not be measurable at 100 yards and shooter skills may not be enough to show the difference between a Good crown and none. When we try to stretch distance out to 1000+ yards, it can have a major effect on accuracy.

The type of crown has little if any effect on accuracy if done correctly, but it can have an effect on durability in service. It is normally one of the last things that a gunsmith does as far as the metal work because it is set up in the lathe and true to the bore. (A must for a "GOOD /concentric crown.

Plus it also add a finishing touch to a fine rifle. most believe that the crown is the last thing the bullet sees, and the last thing that has or can have any mechanical effect on the bullet. Beyond the
crown, the bullet is own its own.

Like so many other things with long range shooting/hunting EVERYTHING IS IMPORTANT To achieve the best accuracy.

Just my opinion

J E CUSTOM

 

[hammer111]

That's what was what have always thought it was for, but I didn't know that it only effected accuracy at longer distances.

 

[J E Custom]

That's what was what have always thought it was for, but I didn't know that it only effected accuracy at longer distances.

Factory rifles notoriously have poor crowns and typically don't shoot that well because of many things, but the crown is most often part of the accuracy issue.

The effect of a poor crown is minimal at short distances and even though it is minimal, at longer distances it increases because of the initial error/deflection.

So It effects accuracy at the short distances also. (It Just does not show as much).

J E CUSTOM

 

[hammer111]

Very good info thanks.

 

[Boe]

A bad crown effects accuracy regardless of distance. I've had rifles that came in my Shop that shot 6" groups at 100 yards. A poorly cut crown is just that a poorly cut crown.

Richard Hilts
Hilts Accuracy Custom Rifles

 

[MudRunner2005]

So crowns have nothing to with accuracy or not that much as you would think ?

Crowns affect the pattern of gas dissipation as the bullet exits the muzzle. Which, if damaged or unevenly/improperly cut, can cause the bullet to slightly yaw a particular direction as it exits the muzzle. This yawing affect will cause accuracy issues which will expound itself, the farther you increase your shooting distance.

 

[hammer111]

Next question would be how do you know your gun has a bad crown. Can any crown be made better. Can a gunsmith tell if a gun has a bad crown.

 

[Boe]

Yes, A reputable Riflesmith can look at it with a bore scope or loupe and determine if it needs to be replaced. The only way to repair the crown is to recut it. I prefer to indicate on the lands and grooves of the bore before machining the crown

Richard Hilts
Hilts Accuracy Custom Rifles

 

[hammer111]

Boe have you done any crown work with the bmag skinny barrel. Did it help.