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pitting in bore riling

Posted: Tue Dec 21, 2010 11:22 pm
by denong
hi guys,

i have a micro grooved brno 2. just recently while cleaning i noticed that a pit has developed breaking one of grooves at one point about 1.5" from the muzzle, for now i still have good accuracy but for how long can anyone advice, also can it be repaired. i just hope it not the begining of the end of my rifiling.

regards

Re: pitting in bore riling

Posted: Wed Dec 22, 2010 1:58 am
by TwoRivers
A small pit 1 1/2 " from the muzzle is not likely to affect accuracy. Whether it will get worse depends on cleaning and storage conditions. It cannot be repaired. It can be gotten rid of by either shortening the barrel, or counterboring, should it ever affect accuracy.

Re: pitting in bore riling

Posted: Wed Dec 22, 2010 9:48 am
by dr.jayakumar
i know how you feel.i had the same, when i found that my pistol bore had a bulge,due to improper ammunition.later i found out that it doesn't spoil the accuracy.so don't worry,use proper ammo,so that it does not rip off the sharp edges.you may fill it with some lead so there won't be any sharp edges,hope you understood what i meant.have fun.

Re: pitting in bore riling

Posted: Wed Dec 22, 2010 10:25 am
by gajamacho
My Mentor (who was also a great shot) once told me :- If your bullet finds the mark, do not worry .

Since you are talking bout a .22, you do not need to worry about further damaging the rifling.

Re: pitting in bore riling

Posted: Thu Dec 23, 2010 12:33 am
by denong
hi guys

thats quite comforting to hear positive and hopeful advices, but lately it is physcologically affecting my shots. by the way how do u fill lead.

regards

Re: pitting in bore riling

Posted: Thu Dec 23, 2010 1:52 am
by TwoRivers
"fill it with lead"? Just shaking my head in wonder.

Re: pitting in bore riling

Posted: Thu Dec 23, 2010 6:48 am
by The Doc
TwoRivers wrote:"fill it with lead"? Just shaking my head in wonder.
Just imagine a barrel scope (connected to a video camera and a TV monitor) from the action side and a thin heated probe carrying a molten drop of lead from the muzzle end , visualize the crater ,drop the lead and fill up the defect. Withdraw the probe and smoothen the area with a tiny motorised burr once the lead cools down. (This imagination is greatly inspired by my profession of being an Arthroscopist) :lol:

Next fire a couple of shots ---- BANG---BANG ----- the crater is back and ........

oops is that a ring in there as well ? :mrgreen:

best,
Rp.

Re: pitting in bore riling

Posted: Thu Dec 23, 2010 7:15 am
by nagarifle
nay lead is no good, use bostick mixed with metal dust or the dentist filling :lol:

give it a good clean remove all the rust. do not over do it. keep an eye on it. if the bore is pitted(tiny holes rusted into the barrel) there is noting you can do to fill it. you can have it rebarrel or have it relined. it should not effect accourcy,

Image

Re: pitting in bore riling

Posted: Thu Dec 23, 2010 9:18 am
by dr.jayakumar
take a drop a lead{melted,maybe using a soldairing rod} place it over the pit.excess can be scraped with a fine file.take a few shots and you will see it sitting tight.tried with air rifle,stays for about hundred shots.

Re: pitting in bore riling

Posted: Thu Dec 23, 2010 10:27 am
by gajamacho
MOderators :- Guys, we need some stringent filtering here as some wrong advise may endanger the life of the shooter. ..there seems to be many clowns on the forums .

Re: pitting in bore riling

Posted: Thu Dec 23, 2010 10:35 am
by dr.jayakumar
gajamacho wrote:MOderators :- Guys, we need some stringent filtering here as some wrong advise may endanger the life of the shooter. ..there seems to be many clowns on the forums .
''you can be straight if i am wrong'' read'' lead laping''

Re: pitting in bore riling

Posted: Thu Dec 23, 2010 11:07 am
by MoA
While it is possible to lead lap some rifles, I doubt you can do it with a .22 lr. If it is affecting you, sell the rifle and get another one. :cheers:

Re: pitting in bore riling

Posted: Thu Dec 23, 2010 12:19 pm
by gajamacho
dr.jayakumar wrote:
gajamacho wrote:MOderators :- Guys, we need some stringent filtering here as some wrong advise may endanger the life of the shooter. ..there seems to be many clowns on the forums .
''you can be straight if i am wrong'' read'' lead laping''
Boss,

This is a specialised job to be undertaken by a professional gunsmiths only. The way you put it sends out a wrong message to DIY kinda guys. i hope the members agree with me.

UNQuote -<take a drop a lead{melted,maybe using a soldairing rod} place it over the pit.excess can be scraped with a fine file.take a few shots and you will see it sitting tight.tried with air rifle,stays for about hundred shots.>

Re: pitting in bore riling

Posted: Thu Dec 23, 2010 1:31 pm
by nagarifle
the ballistics of air rifle and RF/CF rifles are not the same. Thus they should not be treated on par with air rifles. To do so is asking for some very serious hospital treatment or a plot of ground 6feet x6 feetx3feet or a ruddy big bombfire.

lead lapping/barrel lapping is a process which leaves the barrel polished by removing the
imperfections in the barrel giving it a mirror like finish, it also removes tooling marks left from the rifling process.

" A steel rod is inserted from the breech end of an unchambered barrel and stopped an inch or two from the muzzle. Then, molten lead is poured into the bore to form a lead slug.

Once the lead sets up, the rod is pushed out of the muzzle and the lead slug is coated with a mix of oil and lapping compound. The slug is then pulled and pushed back and forth through the barrel.

When you do this, even with a very well made barrel, you can actually feel differences in resistance as the lap goes through. Spots that are tight may get a little more attention. It is a job that requires a certain skill."

Re: pitting in bore riling

Posted: Thu Dec 23, 2010 2:28 pm
by TwoRivers
Naga: Don't know where you got that quote, but as written it won't work. Also, if you could lap all of the bore to get a pit out, you'd have an oversized bore. If you just lap 2" from the muzzle, you have a belled muzzle, and accuracy gone out the window.

The Doc's suggestion is by far the best. Could be a lucrative sideline. Only one thing, for the solder to bond, the work has to be hot enough to melt the solder. So we'll need a micro torch as well. Or we could heat up the whole works. But don't forget to take the stock off. As to putting a file down the muzzle of a rifle.....get that gun away from that guy. :mrgreen:

There must be some dentist on the forum. In my opinion, he'd be most qualified to fill a pit without doing too much damage to the rifling. Any takers? :lol:

Coming next week: Darwin Awards.