Counterboring for Milsurps

[Drachenblut]

Hello All,

I have some questions. I have recently learned how important the "crown" of the rifle is, and have a couple rifles that look like someone dug posts with the barrel tips... does counterboring badly devalue a rifle? How far back does counterboring have to go to be effective? Prices and gunsmiths able to do this service?

- D

 

[eos]

Counterboring is routinely used to restore accuracy to a worn crown. Common milsurp repair, just about every country used it to extend barrel life.

Gunsmith will probably apply whatever minimum shop charge is in effect. Not usually a complicated matter.

 

[Ryan j]

I've shot some pretty straight shooting old rifles that were counterbored.
If your rifles look like they were used to dig post holes I wouldn't worry about having the barrels counterbored depreciating them too much....

 

[Hitzy]

If it's just the crown, a smith can recrown it for you. If the rifling is pitted or worn at the muzzle, then you could look at counterboring.

 

[Drachenblut]

Now, question, does pitting down the barrel cause a major loss of accuracy? I have a couple rifles that have a few pits and wonder if theres any way to do anything about it?

 

[Hitzy]

Now, question, does pitting down the barrel cause a major loss of accuracy? I have a couple rifles that have a few pits and wonder if theres any way to do anything about it?

A bit of pitting wont hurt accuracy much, but may foul quicker....so instead of getting a few hundred accurate rounds between cleanings, you might be looking at <100 or in real bad cases <10
Some guy sells lapping bullets in the US, but really, it's pointless.

 

[glang1]

I'd stay away from lapping bullets if I were you. They cause throat erosion that can affect accuracy even worst. If you feel you must lap your barrel, do it with a rod & lapping compound.

 

[Drachenblut]

Pardon me? Lapping your barrell? Please explain.

 

[john@]

"sanding" the bore of a barrel with a wet muddy grinding compound, similar to how you grind valves in a ICE to give them a fresh seat.

 

[Drachenblut]

the words "bore" and "sanding" do not sound good... would that not remove your rifling? I once used something called JB Borepaste to remove all sorts of debris from the inside of a WWII Mauser once... same concept? How deep are pits usually anyways?

 

[john@]

I exagerage for the purposes of illustration. The compound that is used is like a paste with fine grit in it. More like using very fine wet emery cloth.

Should not remove the rifling as all surfaces will be affected equally.