Just what is 'Crown' then?

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Oyeboten

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Everyone seems to be speaking of 'Crown' as though it were only the couple of thousanths of de-burring Chamfer or Bevel immediate to the Bore, done to eliminate feathers or burrs.


I had thought the term 'Crown' would mean the overall shape and rounding of the Muzzle-end itself, which as an incidental, includes the minute chamfer or bevel immediate to the Bore proper for eliminating burrs or feathers.


So...are we sure of the nominclature on this?


I doubt anyone in the Old Days would have called a minute de-burring Bevel, a 'Crown', then had no word or term for the treatment of the general end of or rounding of a Muzzle...


Or, called merely a minute bevel after cutting a Barrel, a 'Re-Crowning'...


Confused...



Phil
 
Many years ago, folks like the Winchester factory faced the muzzle off flat and deburred the hole and outside edge.
That was / is the crown.

Later, muzzles were rounded off to a radius and deburred.
That is also a crown.

More recently, we have seen every variation of angles, countersinks, counterbores, reverse tapers, and cute sayings engraved on muzzles.
I guess that is a crown too?

rc
 
"RC's posts make me smile"
Click to expand...

Me too. :)


"More recently, we have seen every variation of angles, countersinks, counterbores, reverse tapers, and cute sayings engraved on muzzles.
I guess that is a crown too?"
Click to expand...

The more elaborate are called "The Tiara" if they're formed by a CNC process.
 
I thought "crown" was the uniform treatment of the end of the muzzle to allow the gases behind the bullet to uniformly dissipate, so that undue influence from a burr or irregularity would not "push" the bullet one way or the other off of center as it leaves the bore.

Man, that was a long sentence. I think it was a sentence.
 
"the professionals on here never comment on my work"

Chuck it could be that the words fail them, then again it could be that nasty old "J" word.
 
Agree with RC. My original Winchester Single Shot has a nice flat muzzle, beveled outside just enough to keep from gouging a gun case, inside just enough to "sharpen the rifling."
My Japanese Browning "highwall" has a deep concave muzzle which protects the bore from knocks, but accumulates black powder fouling worse.

Dan Wesson used to advertise the "ugly muzzle" on their shroud-and-tube revolver barrels. The tube was just faced off flat and smooth, not even a slight bevel. They said it gave even bullet exit and improved accuracy. May have been something to it, they were popular in the revolver division of Handgun Metallic Silhouette out to 200 metres.
 
There are 'smiths who say the crown is how the rifling at the muzzle is finished and only goes out past the groove diameter a few thousandths.

The rest of the barrel's front end is called the "face" and that's the part that can be flat or rounded.
 
Oyeboten, you're welcome.

Some years ago, a friend of mine clamped his .308 Win. match rifle in a machine rest and the barrel was faced at 0 degrees (flat, perpendicular to the bore axis) and he tested it at 300 yards. I grouped well over 2 inches.

He faced the muzzle to an 2 degree angle then recrowned the lands with a half inch crowing ball and lapping compound. It shot a bit under 2 inches.

After increasing the recessed face angle 2 degrees each time, recrowning the lands then testing again, all the way down to a 16 degree face, the groups went down to well under 1 inch then back up to near 2 inches.

He figured the best accuracy was with both 10 and 12 degrees recessed face, so he decided to face his barrels to an 11 degree angle. For some reason, that's become a well followed standard in target rifles.

As the barrel doesn't know what kind of rifle it's being used in, any barrel may well benefit from an 11 degree flat face regardless of how it's used.
 
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Hi Bart,




So...what has seemed best then, when the utmost in Accuracy is desired, is for the Crown to be 11 Degrees off of the '90' Degrees which is perpendicular to the long axis of the Bore? ( Whatever the face as-such may be doing?)
 
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Oyeboten, I noticed my typo/error, changed "crown" to "face" so it would be correct. I've sometimes got the two mixed up.

The muzzle's faced to 11 degrees then the bore edge is crowned to get rid of the burrs left from facing.

Be sure the muzzle's faced with the lathe tool moving from the bore outwards so there's minimum peeling.
 
Hi Bart,



Oh...Okay...


Understood...


Much obliged.


Good to know!


A long time ago, I read the old Book "The Bullet's Flight" by F.W.Mann.


I do not recall now though, if he'd explored Facing angles in his quest for formailizing the criteria for consistant accuracy.



Phil
 
Evert suggests:
so, can one describe a "crown" as a burr-free muzzle on a gunbarrel, regardless of angle?
Click to expand...
Yes. 100 percent right you are. I'm half Norwegian and I was only half right earlier getting mixed up between "crown" and "face."

Anyway, my wife and I will be cruising Norway's coast from Bergen around the top to Kirkenes this November. Could you please ask the electric power company powering and controlling the Northern Lights to put on an extra special display for us? We'll be eternally indebted to you. Thanks.
 
ahh: travelling by the "hurtigruta" boat?

ill tell'em to turn on the northern lights and let the polarbears out for ya!
 
"...There is also "Crown & Coke"..." Don't be ridiculous. Crown Royal isn't made to be ruined by mixing it with Coke. Or anything but a little water. You philistine, you.
"...100 percent right you are...." Absolutely. Think in terms of how the gases come out of the barrel with the bullet. If the muzzle has a low spot, for example, the gases will not come out directly behind the bullet. That can and will throw the bullet off a wee bit.
 
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