center punch crown of barrel for accuracy ???

[lone ranger]

I was talking to an old hunter and he said they use to center punch the Crown of the barrel to change the point of Aim.

Punch the top face of the crown to lower , punch the left face to hit right and so on.

He said 'YOU GIVE IT 1 GOOD WACK" with a punch . He said it was done alot back in the day and it worked.
He said most black powder guns were sighted in this way, as they had NON adjustable sights.
I never heard tell of this before. Have you ? or have you ever done it ?

 

[Potashminer]

I had not heard that - an "old hunter's" story?? But, recently on this site, it was posted that apparently the Cooey factory in Cobourg, Ontario, would install iron sights to centreline of barrel, then test fire in a vice. Then, adjust by bending barrel as needed to get bullet holes matching sights... It is never a certainty that the bore of the barrel is dead centre or dead straight with the exterior of the barrel.

But, no doubt somebody in middle of no-where fell onto a rock and dinged up his muzzle badly, and needed to do "something"..,

 

[MechanicalSparky25]

Sounds HIGHly precise.

It sounds like many of the things I have done in my life that make me question why I did them after the fact.

Tagged for interest

 

[Grizzlypeg]

Gun barrels and sausages, you don't want to know what went into the making of either from the sounds of it. Or is that only when both are prepared by a butcher?

Some gunsmiths that use the through the headstock chambering technique, mark the high point of the muzzle bore in the barrel, and make sure to time the barrel so it points upwards. But I guess when you bought a cooey for $20, they had to use some shortcuts.

 

[lone ranger]

I wonder,..is anyone old enough on this forum to remember this being done. The fellow I talked to was 97.
Maybe this is a black powder thing.

 

[chappy]

center punching a crown will insure one thing a damaged rifle and a trip to your local gunsmith.

 

[pjs]

I wonder,..is anyone old enough on this forum to remember this being done. The fellow I talked to was 97.
Maybe this is a black powder thing.

Consider that at 97 he could be a bit confused.

 

[lone ranger]

Consider that at 97 he could be a bit confused.

well, you may be right,...but he certainly remembered the early days.

 

[Blastattack]

well, you may be right,...but he certainly remembered the early days.

The early days? Of 1940? Black powder was just about as niche then as it is now. Not sure what early days that might be referring to...

 

[lone ranger]

The early days? Of 1940? Black powder was just about as niche then as it is now. Not sure what early days that might be referring to...

lets try keep this thread technical please.

I know when we use to weld cracked engine blocks,..you had to Peen them before welding.
I suppose it Shifts the metal ever so slightly.

 

[guntech]

Well no doubt it would affect point of aim... and possibly accuracy... but it is not something I would do a rifle of mine.

 

[Grizzlypeg]

lets try keep this thread technical please.

I know when we use to weld cracked engine blocks,..you had to Peen them before welding.
I suppose it Shifts the metal ever so slightly.

I've heard of peening the hot weld on cast to relieve stress in the metal, reduce the chances of cracking.

 

[legi0n]

I've heard something similar but instead of peening, the crown would be ground on the side one wanted the poi to move towards
The idea was that the base of the bullet would experience less pressure where the crown first let the gas vent and consequently steer.
I guess all chinese side by side shotguns are regulated this way
too bad the mythbusters split

 

[legi0n]

apparently there's truth in it:
https://rifleshooter.com/2018/03/do-rifle-crowns-matter-does-a-crown-effect-accuracy/

Turns out the cut (about 30º) shifted my point of impact (POI) about 16 MOA.

 

[lone ranger]

After a Ton of searching the web I found this-


"Here is an old Gunsmithing trick that has served me very well over the years with customers guns that shot so high or low or wdely that this was the only solution: If the muzzlecrown is sufficiently wide, then you can place a centerpunch midway between the bore and the outside and while holding both the gun and the punch securely, hit the punch only one good rap with a ballpeen hammer. That is the method, but this is the proceedure: If the gun is shooting to the right then punch the muzzlcrown to the right of the bore. Punch and testfire repeatedly in the selfsame hole until the gun shoots true. Then file the crown to hide the dimple. Originally used on muzzleloaders, this works well on fixed site revolvers and even on modern rifles too."


Found this on SHOOTERS FORUM

 

[Potashminer]

I think I would want to hear that it worked on one of your rifles, before I tried so on one of mine. Just too easy to use a Brownells hand tool to re-cut the muzzle square, then beveled; bent barrels have been straightened by barrel makers and "smiths" for 100 years or more - not so sure what the centre punch idea would be a solution for?? Note the above quote - "then file the crown..." .

 

[BrotherRockeye]

lets try keep this thread technical please.

I know when we use to weld cracked engine blocks,..you had to Peen them before welding.
I suppose it Shifts the metal ever so slightly.

I had to chuckle at "technical" used in a thread about center punching a barrel crown but the info that follows is very interesting.

I'm not surprised that back in the day manual manipulation was used to make a difference in poi. Where there's a will...

 

[new210/22]

center punching a crown will insure one thing a damaged rifle and a trip to your local gunsmith.

Two things.

 

[tigrr]

I knew a duck hunter who stuck his barrel in a vise and reefed on it to get it to shoot to point of aim. Rifle barrel??????

 

[flyr]

We used to bend airgun barrels up to compensate for "droop" when using a scope.
This was before "droop compensating" scope mounts were available.