yep got to thinking again.

fiver

Well-Known Member
so why are barrels crowned with a concave face.
why don't they get a convex slope to the end of the barrel in a cone shape?
it seems that the gasses would be easier to mitigate away from the base of a bullet if they made little to almost no contact with the face of the barrel.
I can't be the only one that's ever thought of this, but I have never read nor heard of anyone trying it.
would it work?
be too fragile?
screw up the nodes?
no idea?
dammit now I gotta try it?
 

Rick

Moderator
Staff member
Had a couple of custom Shilen barrels with such a crown. Not a new idea for sure. Factory probably do it whichever way is cheapest, not which way is best.
 

Rally

NC Minnesota
Seems like it would be too fragile in a cone shape, for the average hunter who probably drops a gun or two in a lifetime.
Were those Shilen barrels actually cone shaped Rick?
 

Ian

Notorious member
Recessed or cone crowns are purely for protection during handling.

I read somewhere that a long-range precision rifle building outfit tried everything from flat to 45 degrees and found it didn't make any difference whatsoever to groups.
 

RicinYakima

High Steppes of Eastern Washington
The above experiment has been done and published at least ten times in the last 30 years. Crowns make very little difference, including running a rattail file inside the end of barrel. However what it does do is shift the center of the groups, up to several inches. So protecting the muzzle is important, but it doesn't make groups size smaller. FWIW, Ric
 

Cherokee

Medina, Ohio
Then I got'a ask, why do some custom gunsmiths (in my 50 years of reading gun mags) make a big deal about how the barrels are crowned, why include re-crowning as a custom feature in rebuilding some guns ?
 

Intheshop

Banned
Part of the issue is "process engineering".

How long does the tooling stay "sharp"-devided by- the methodology that particular maker uses to achieve a maintainable tolerance.
 

RicinYakima

High Steppes of Eastern Washington
Cherokee, It is a simple process, requires little or no tooling, and is a "high profit" service for a gunsmith to offer. It goes with all the other gun rag myths: harder bullets don't lead as much, the old 30/30 is only good for 50 yards with iron sights and then can only kill sickly armadillos, etc.
 

Ian

Notorious member
Then I got'a ask, why do some custom gunsmiths (in my 50 years of reading gun mags) make a big deal about how the barrels are crowned, why include re-crowning as a custom feature in rebuilding some guns ?

I agree with Ric, it's a way to get income for a service that may or may not be "needed". Another thing is it may be a time-saver that brings extra income if the barrel is being processed in such a way that it needs a hardened, live center shoved into the bore. If you don't have to worry about screwing up the crown, putting a center in the muzzle can remove a time-consuming process of supporting the muzzle end from the outside and indicating the bore on center with a pin and test indicator. Afterward, throw it in the chuck, single-point a new crown right quick, touch it with a brass lap, and ta-daa...money in the bank.
 

popper

Well-Known Member
Light years ago I was given a worn out 22 rifle. The kind with the F.P. you pulled to cock and the sear(?) was a circular groove (worn rounded so it was a POS rifle) in the F.P. Anyway, cut the barrel shorter with hacksaw. Yup. POI changed. If you don't damage the bullet at the crown, no effect on the path. If it is crooked, POI changes as the HV gas will 'push' one side of the base. Another reason the 'crown' is important - sights and barrel are co-linear. Do you rally want to compensate off-axis as well drop for POI at distance?
 

RicinYakima

High Steppes of Eastern Washington
OK guys, I didn't' say it wasn't important, just not the way most people think. At three hundred yards benchrest with cast bullets from a military rifle, it becomes an effort to re-zero at every range if it isn't close to straight. For shooting deer at 100 yards, hacksaw is close enough. But it will be ugly and your friends will laugh and dog will curl his tail between his legs and hide behind the pickup.
 

Eutectic

Active Member
Around here I have seen an increase in rifles in pickups muzzle down while hunting. I was taught that a rifle doesn't stand on its muzzle unless the barrel if full of solvent! So some type of recess at the crown may help some with this habit. See a lot of muzzles polished bright with dings!

Land wear from years of cleaning from the muzzle seems to affect accuracy more than crown configuration or even minor damage to it.
 

popper

Well-Known Member
The guy in the posted didn't mention the co-linear thing, sort of bypassed it. A guy at the range had a shotgun he'd hacked the barrel off (not sure it was even legal, also had cut off the stock to make a pistol) couldn't hit a single clay.