Counter-bore ............. Why?

To protect the manufacturer's reputation against dumb owners, the idea being it's harder to hit something countersunk than something flush.
 
I've read somewhere that it can be a form of tuning...I've seen a couple of sporters with counter bore that shot well,
 
earlm said:
I've read somewhere that it can be a form of tuning...I've seen a couple of sporters with counter bore that shot well,
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You could counterbore
in a ways with a boring bar to create a tuner, but with EDM, you could go much deeper.
This might take some trial and error. LOL---Ha Ha
 
If you mean "back bored" as opposed to a slightly radical crowning technique, it can do a lot of things, including freeing the bullet from the barrel more quickly before the barrel deviates away from that perfect aim you had when you first thought to push the trigger. My favorite .22 has an 11" backbore to it, but it wasn't actually made by backboring per se. There are easier, better ways to do it.

Brent
 
BrentD said:
If you mean "back bored" as opposed to a slightly radical crowning technique, it can do a lot of things, including freeing the bullet from the barrel more quickly before the barrel deviates away from that perfect aim you had when you first thought to push the trigger. My favorite .22 has an 11" backbore to it, but it wasn't actually made by backboring per se. There are easier, better ways to do it.

Brent
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Brent i appreciate your comments as always. When you have time if you could expound a bit on..
There are easier, better ways to do it.
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I'm hoping a light bulb may go off for me. thanks, joe
 
The barrel is a Lilja that was cut and crowned at 17" long after being turned to about 0.6" diameter and then inserted inside an original 28" Winchester barrel that had been through-bored to 0.6". It is a relining but with a very short liner relative to the barrel and a much better quality "liner" than is the norm.

It has proven to be extraordinarily accurate even in bench use though the rifle was originally intended to be an all out offhand rifle. So, a few other friends saw this and have done more or less the same thing, but each as found exceptional accuracy as a result. I think the reason has more to do with a "tuner" like effect than it does with the bullet's residence time in the barrel.
 
My sporter barrel is counterbored about 2". I suspect it is a way of tuning the barrel. On other barrels that aren't very deep, it is a way to keep from dinging the crown I believe and in some cases, I think quite SEXXXXY! The best way I have found to keep crowns from damage is to have the Smith turn a 45* on the muzzle on the inside. That-a-way the Brush and Jag damage is minimized. I have had my CF rifles done that way for years and never seen one iota of loss in accuracy. ( A 90* crown is asking for trouble you don't need IMHO.)
 
Ah, backboring!

Iron sight shooters sometimes do it so that the foresight clamp has no chance of distorting the barrel at the muzzle. You can bore that lst inch or so that the manufacturer wants your smith to cut off & not waste good rifling.
 
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It is more work trying to tune with back boreing..... I think it was the Winchester 52E's that were back bored a 1/4 of an inch or so. Was this "countersink/back boreing" a form of tuneing? joe
 
jGEE said:
It is more work trying to tune with back boreing..... I think it was the Winchester 52E's that were back bored a 1/4 of an inch or so. Was this "countersink/back boreing" a form of tuneing? joe
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1/4 inch would be for protection from hitting the crown it would have zero tuning effect.
 
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