Stupid question on barrel Crown

Aaron1100us · June 13, 2013, 05:45 AM

Ok, the crown is the end of the barrel that is rounded. I've heard people say they have to get their gun recrowned or they shorten the barrel and have to recrown.

Does the crown do anything? All of my rifles have a crown except my Stevens Favorite model 17 .22. The end of the barrel is cut straight. Can a crown be damaged? How and what does it affect?

MTSCMike · June 13, 2013, 06:34 AM

A flat crown doesn't protect the rifling in case of an impact to the muzzle. If an impact dings or dents the muzzle and deforms the bore exit then accuracy will suffer. There are a wide variety of crowns that can be cut. They can be rounded, recessed (counterbore), cone shaped, etc. They must be cut concentric and flush to the bore for the best accuracy result but their main function is to protect the muzzle from damage.

Aaron1100us · June 13, 2013, 07:03 AM

Thanks. That makes sense.

4EVERM-14 · June 13, 2013, 02:21 PM

Additionally the crown serves another important function. As the bullet exits the muzzle propellant gases escape. The crown serves as a guide for the gases to follow. Uneven pressure around the base of the bullet caused by a nick, flaw or irregularity in the crown can push the bullet base slightly off line as it exits the muzzle effecting accuracy. A clean and even crown is an important part of very accurate rifles regardless of caliber.

spanishjames · June 14, 2013, 12:07 AM

The crown is at the end of the rifling inside the barrel. The end of the barrel can be any shape, flat or rounded, so long as the rifling itself is protected.

James K · June 15, 2013, 01:15 PM

Technically, the crown is the whole end of the barrel, rounded or not, but it is the bullet exit point that is important; the rest is just decoration. An even bullet exit is needed for accuracy. From the other point of view, that is why the base of the bullet is very important to accuracy; a bullet point can be damaged with little effect on accuracy, but a chipped or uneven base can really throw the bullet off.

Jim

Fire_Moose · June 16, 2013, 02:34 AM

I read an article on one of these forums where they progressively damaged the crown and recorded results.

By the end they are carving chunks out of the last 2" of bore. Interesting results.

Ill post a link if no one else does before I find it.

publius · June 16, 2013, 02:43 PM

As others have mentioned, if you damage the crown, (dropping it muzzle first on the rocks or concrete, or improper cleaning.) A crown can be pretty much any concentric shape, recessed, round, you could even take a hacksaw and cut the barrel off flat, all designs must be precise, ( perfectly even ) so the bullet and expanding gasses leave the barrel evenly. Anything to upset this eveness will result in poor accuracy.

Bart B. · June 16, 2013, 03:03 PM

Some call the crown just the edge of the bore where rifling ends and the rest of the muzzle from the crown to the outer diameter the face. Many match rifle barrels have an 11 degree face and a 45 degree crown that goes a few thousandths out from groove diameter.

Fire_Moose · June 16, 2013, 06:27 PM

Not.the one I was thinking of.....

http://www.accuratereloading.com/crownr.html

June 13, 2013, 05:45 AM	#1
Aaron1100us Senior Member Join Date: December 19, 2011 Posts: 235	Stupid question on barrel Crown Ok, the crown is the end of the barrel that is rounded. I've heard people say they have to get their gun recrowned or they shorten the barrel and have to recrown. Does the crown do anything? All of my rifles have a crown except my Stevens Favorite model 17 .22. The end of the barrel is cut straight. Can a crown be damaged? How and what does it affect?

June 13, 2013, 06:34 AM	#2
MTSCMike Senior Member Join Date: March 15, 2011 Location: Middle TN Posts: 164	A flat crown doesn't protect the rifling in case of an impact to the muzzle. If an impact dings or dents the muzzle and deforms the bore exit then accuracy will suffer. There are a wide variety of crowns that can be cut. They can be rounded, recessed (counterbore), cone shaped, etc. They must be cut concentric and flush to the bore for the best accuracy result but their main function is to protect the muzzle from damage. __________________ IDPA Member A00640 Founding Charter Member - Middle Tennessee Shooter's Club

June 13, 2013, 07:03 AM	#3
Aaron1100us Senior Member Join Date: December 19, 2011 Posts: 235	Re: Stupid question on barrel Crown Thanks. That makes sense.

June 13, 2013, 02:21 PM	#4
4EVERM-14 Senior Member Join Date: November 12, 2006 Location: Pennsy Posts: 720	Additionally the crown serves another important function. As the bullet exits the muzzle propellant gases escape. The crown serves as a guide for the gases to follow. Uneven pressure around the base of the bullet caused by a nick, flaw or irregularity in the crown can push the bullet base slightly off line as it exits the muzzle effecting accuracy. A clean and even crown is an important part of very accurate rifles regardless of caliber. __________________ David NRA Benefactor Member Distinguished Rifleman #731 Presidents 100

June 14, 2013, 12:07 AM	#5
spanishjames Senior Member Join Date: April 27, 2010 Posts: 553	The crown is at the end of the rifling inside the barrel. The end of the barrel can be any shape, flat or rounded, so long as the rifling itself is protected. __________________ Regret for the things we did can be tempered by time; it is regret for the things we did not do that is inconsolable." -Sydney J. Harris

June 15, 2013, 01:15 PM	#6
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	Technically, the crown is the whole end of the barrel, rounded or not, but it is the bullet exit point that is important; the rest is just decoration. An even bullet exit is needed for accuracy. From the other point of view, that is why the base of the bullet is very important to accuracy; a bullet point can be damaged with little effect on accuracy, but a chipped or uneven base can really throw the bullet off. Jim

June 16, 2013, 02:34 AM	#7
Fire_Moose Senior Member Join Date: January 16, 2013 Posts: 211	Re: Stupid question on barrel Crown I read an article on one of these forums where they progressively damaged the crown and recorded results. By the end they are carving chunks out of the last 2" of bore. Interesting results. Ill post a link if no one else does before I find it.

June 16, 2013, 02:43 PM	#8
publius Senior Member Join Date: January 25, 2005 Location: Mississippi/Texas Posts: 2,505	As others have mentioned, if you damage the crown, (dropping it muzzle first on the rocks or concrete, or improper cleaning.) A crown can be pretty much any concentric shape, recessed, round, you could even take a hacksaw and cut the barrel off flat, all designs must be precise, ( perfectly even ) so the bullet and expanding gasses leave the barrel evenly. Anything to upset this eveness will result in poor accuracy. __________________ "Suppose you were an idiot, and suppose you were a member of Congress, but I repeat myself." Mark Twain

June 16, 2013, 03:03 PM	#9
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	Some call the crown just the edge of the bore where rifling ends and the rest of the muzzle from the crown to the outer diameter the face. Many match rifle barrels have an 11 degree face and a 45 degree crown that goes a few thousandths out from groove diameter.

June 16, 2013, 06:27 PM	#10
Fire_Moose Senior Member Join Date: January 16, 2013 Posts: 211	Re: Stupid question on barrel Crown Not.the one I was thinking of..... http://www.accuratereloading.com/crownr.html