View Full Version : crowning on guns
richard pries
10-15-2017, 05:23
how come a rifle is crowned and some hand guns are not. my 22 ruger mark 11 is not and neither is a high standard . or a 1911
they all have a crown, some are flat, some are rounded, and some are recessed.
richard pries
10-15-2017, 06:24
If it is flat it has no crown
If it is flat it has no crown
mmmm no.
High Plaines Doug r
10-15-2017, 07:04
mmmm no.
My Ruger Mark II has no crown. The face of the muzzle is flat with a chamfer at the bore. When properly done, without damage, it serves it's purpose. A crown serves to protect the muzzle from (some) damage.
clintonhater
10-15-2017, 08:16
My Ruger Mark II has no crown. The face of the muzzle is flat with a chamfer at the bore...
That chamfer is the crown.
clintonhater
10-15-2017, 08:18
A crown serves to protect the muzzle from (some) damage.
If you're referring to the radius cut seen on some muzzles, that's not actually part of the crown.
High Plaines Doug r
10-16-2017, 09:42
Apparently there seems to be a debate as to the definition of what exactly a "barrel crown" is.
Fine. Carry on.
Johnny P
10-17-2017, 07:18
Regardless of how it is done, crowning is the cleaning up of the muzzle so that the bore is absolutely concentric at the muzzle. Some are flat with just a slight chamfer, while some are rounded(as on the 1903 Springfield), and some are recessed. Whatever they are the chamfer of the bore is the last step in crowning the barrel.
Several years back I bought a Colt Match Target AR15 which had a SS barrel with recessed crown. My first trip to the range was a big disappointment as it was shooting 2 1/2 to 4 1/2 inch groups at 100 yards off the bench. While cleaning it I noticed that it had a slight wire edge about half way around the bore as if they lifted the cutter just as it got to the bore. There was absolutely no chamfer plus the slight wire edge. I had the bore chamfered and it shot like it should have.
clintonhater
10-17-2017, 07:55
I had the bore chamfered and it shot like it should have.
Not a hard job to do yourself without a lathe, unless the muzzle has been badly mutilated. With the muzzle held upright in a vise, chuck a round-headed brass screw in a drill (hand-operated is easiest to control), apply valve-grinding compound to the screw-head, and chamfer as needed; it's a method illustrated in many old gunsmithing books, and yes, I've done it myself. Size of screw needed varies with size of bore.
PS--Wouldn't work for obvious reasons with a recessed crown.
JB White
10-17-2017, 09:11
I used the brass screw & compound on a 22WMR and it brought the pattern over to a nice group, and the sights were recentered atop the barrel. It works OK so long as no heavy handedness comes into play. Some may call it "shadetree smithing" and I still think of it as such. However I've known a few guys who try that trick before getting too involved. Some guys use a bullet instead of the brass for polishing.
clintonhater
10-17-2017, 10:27
It works OK so long as no heavy handedness comes into play.
As with so much else in life; but such advice is wasted on the careless or stupid.
"...If it is flat it has no crown..." Nope. "Crown" is just a fancy term for the muzzle. Nothing to do with the shape. A flat muzzle is still "crowned". Kind of early for the semantics arguements.
And the 'bore' is the hole that gets drilled before there's rifling.
clintonhater
10-17-2017, 02:54
A flat muzzle is still "crowned". Kind of early for the semantics arguements.
Evidently not, because until something is done to break the sharp edges of the lands & grooves at the muzzle, it has not been crowned by the common understanding of the term.
just did a little search, and see the same disagreement everywhere as to what is the actual crown. dont see an actual dictionary type definition anywhere, so have fun and argue on.
clintonhater
10-17-2017, 03:53
just did a little search, and see the same disagreement everywhere as to what is the actual crown. dont see an actual dictionary type definition anywhere, so have fun and argue on.
"The beveled edge on the muzzle of a rifle." From Shooter's Bible Small Arms Lexicon.
Even this isn't entirely clear--should have specified inner edge of bore.
Per Hallowell & Co of Livingston, Montana.....
Crown - The finish contour of the muzzle of a rifle. May be flat or rounded. Often shows effective chamfering to protect the critical rifling at the absolute end of the muzzle.
Photo ............http://www.hallowellco.com/crown.htm
http://www.hallowellco.com/abbrevia.htm
http://hallowellco.com/
IE. Cut the end of a barrel off and it will leave a burr and deflect the bullet if fired. Polish the end, where cut, by means of leaving it flat, chamfering, rounding or recessing to the extent that the bullet is not deflected in any way when fired and it will be crowned. This is often seen on Garand barrels where muzzle erosion affects the accuracy. 1/4---1/2" of the muzzle is cut off to where the good rifling extends to the end, then it is re-crowned. On factory barrels the crown is rounded, on re-crowned barrels it is nearly always flat due to homeowners and shops not having the machinery to duplicate the original rounded contour.
Johnny P
10-17-2017, 05:07
Not a hard job to do yourself without a lathe, unless the muzzle has been badly mutilated. With the muzzle held upright in a vise, chuck a round-headed brass screw in a drill (hand-operated is easiest to control), apply valve-grinding compound to the screw-head, and chamfer as needed; it's a method illustrated in many old gunsmithing books, and yes, I've done it myself. Size of screw needed varies with size of bore.
PS--Wouldn't work for obvious reasons with a recessed crown.
Also move the handle of the hand drill in a cone shape while cranking to keep from wearing a groove in the screw head. After this went to a flea market and found a beautiful old Millers Falls hand drill. Only used it to crown one barrel, but love how smoothly the drill operates.
https://s1.postimg.org/9q93gzaqpb/MFD.jpg
Per Hallowell & Co of Livingston, Montana.....
Crown - The finish contour of the muzzle of a rifle. May be flat or rounded. Often shows effective chamfering to protect the critical rifling at the absolute end of the muzzle.
Photo ............http://www.hallowellco.com/crown.htm
http://www.hallowellco.com/abbrevia.htm
http://hallowellco.com/
this is pretty much my accepted definition. having crowned quite a few barrels, and purchasing special tooling for it.
clintonhater
10-17-2017, 06:56
After this went to a flea market and found a beautiful old Millers Falls hand drill. Only used it to crown one barrel, but love how smoothly the drill operates.
This is exactly what I've used in the past! Easily controllable, unlike an electric drill.
JB White
10-18-2017, 08:00
I still have one of those around here someplace. Probably in a box with the bit braces and yankee driver.
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