Can somone explain to me Counterbore.
- Thread starter Craig0ry
- Start date
If the muzzle of a rifle get's dinged up from poor cleaning technique, it can ruin accuracy. Some guns have had the muzzle counter bored, or drilled out to remove the damaged section without reducing the barrel length and requiring the removal and replacing of the front sights.
I have a couple of old Moisin-Nagants which have been counterbored in Finland and they shoot really nice. Barrels could be countercored for a lot of reasons, but poor cleaning was the main one. Other reasons would include muzzle damage, rust and just about any other awful thing you can think of that might wreck an expensive barrel.
The Finns probably made more use of this technique than anyone else and restored a LOT of old rifles to good-shooting status.
Generally, it is done on a lathe, using a boring-bar. The new internal muzzle then is cleaned up, removing any fangs, bits of swarf.
MUCH cheaper than a new barrel and, if the original rifling still is good, generally can restore the rifle to very decent performance.
Have fun!
The Finns probably made more use of this technique than anyone else and restored a LOT of old rifles to good-shooting status.
Generally, it is done on a lathe, using a boring-bar. The new internal muzzle then is cleaned up, removing any fangs, bits of swarf.
MUCH cheaper than a new barrel and, if the original rifling still is good, generally can restore the rifle to very decent performance.
Have fun!
Counterbored Finns
I also have a counterbored Mosin Nagant, of Finnish descent. It has a very noticeable bulge in the barrel, about 2 inches back from the muzzle.
A guess would be that it was fired with an obstruction (probably snow) in the barrel. The barrel has been counterbored, and accuracy is quite acceptable. It shoots ordinary standard 7.62x54 Ball ammo well under 2 inches at 100 yards, and will come close to one inch with the heavier bullet loadings.
A very fast and cheap way to make a rifle serviceable again.
,
I also have a counterbored Mosin Nagant, of Finnish descent. It has a very noticeable bulge in the barrel, about 2 inches back from the muzzle.
A guess would be that it was fired with an obstruction (probably snow) in the barrel. The barrel has been counterbored, and accuracy is quite acceptable. It shoots ordinary standard 7.62x54 Ball ammo well under 2 inches at 100 yards, and will come close to one inch with the heavier bullet loadings.
A very fast and cheap way to make a rifle serviceable again.
,
Buck Turgidson
Regular
does counter bore reduce value at all???
how can I check my mosins to see it it needs to be done?
if it does need it...should I have it counter bored??
also I have to clean my mosins from muzzle to breach as i do not have a long enough cleaning rod to go from breach to muzzle. were can i find a 36-40" single piece cleaning rod?
how can I check my mosins to see it it needs to be done?
if it does need it...should I have it counter bored??
also I have to clean my mosins from muzzle to breach as i do not have a long enough cleaning rod to go from breach to muzzle. were can i find a 36-40" single piece cleaning rod?
I suppose the highly anal might think so as the piece has been altered from the original. For a good shooter I'd rather have a counter-bored barrel with sound rifling at the end than an original, un-modified barrel with a badly eroded and worn muzzle. AFAIK the only US military piece where counter-boring was a depot level repair, is the M1 Carbine.
You should shoot the rifle to check it's accuracy before contemplating this as it is a tricky job requiring set up in a lathe. I have owned several Garands with muzzles gauging .303 diameter as opposed to the original .300. As long as the crown is concentric without nicks or gouges they shoot acceptably well.
You should shoot the rifle to check it's accuracy before contemplating this as it is a tricky job requiring set up in a lathe. I have owned several Garands with muzzles gauging .303 diameter as opposed to the original .300. As long as the crown is concentric without nicks or gouges they shoot acceptably well.
