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empirevr
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Reged: 03/09/06
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Loc: England,but now Italy.
Pitting,once again.....
      #64280 - 19/10/06 09:00 AM

Hi all, lets get the blight of pitting out into the open here, yes i did see the other posts on it,but not much was said on the subject,or at least no specific advice was given........

In bp rifles,though im sure it matters in all rifles, what are the problems with pitting,and what are the remedies?

What is light pitting and what is heavy pitting? example 1mm pits, heavy,light,or normal?

What can be done with this problem? apart from re-barelling etc? I understand pits can be filled,with something.....

Anyway,whats bad pitting,and where is the worst area it can be located within the barrels or outside them?

Thankyou

Ben


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Otto
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Re: Pitting,once again..... [Re: empirevr]
      #64300 - 19/10/06 09:47 PM

Clearly, we all want to look at a rifle's bore and see perfection. Many of the "interesting" doubles and single shots we appreciate have bores that are pitted. My worst example of the is a 450 BPE Farquharson. When purchased, it seemed a candidate for rebarreling. Pits started in the chamber, continued into the bore, and were severe. The muzzle was a mess, sort of an oval with hit or miss rifling. Initial shooting with nitro for black 4198 loads behind lead bullets was a joke...shoulda been throwing rocks. Further, the brass had to be knocked out of the chamber with a rod as it had flowed into the chamber pits. Perhaps that is how the muzzle/crown was ravaged. Wanting to save the original barrel, I tried a few "fixes" befor rebarreling. First I sleeved the chamber with chrome-moly, then counterbored the muzzle 'till there was good rifling...about 2" in. Finally, I added an over powder card wad and shotshell buffer to my cartridges, same charge of 4198 and same bullet. Bingo! Consistent 2 1/2" groups at 100yrds. The buffer seems to clean the bore with each shot, as there is no problem with leading. Cases fall from the new chamber. Venturino wrote about his experiences with pitting and bulges/rings. He found that pitted barrels could always be made to shoot acceptably...bulged/ringed barrels sometimes and sometimes not! My thought is that many pitted barrels suffer from bad muzzles, and if cut and crowned or properly counterbored, these barrels would perform surprizingly well.

Otto


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empirevr
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Re: Pitting,once again..... [Re: Otto]
      #64324 - 20/10/06 08:57 AM

Thanks Otto

Sorry so, you sleeved the barrel with chrome moly? what is this? so,you didnt re-barrel?

I couldnt see myself re-barreling,i mean thats OTT i would rather get a gun with slighter pits or none than do that.

Are 1mm pits very bad pitting or??? Sorry i dont know.

Ben


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DarylS
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Re: Pitting,once again..... [Re: Otto]
      #64326 - 20/10/06 10:31 AM

: I have smoothed up some barrels using firelapping and lead bullets. The worse barrel I did turned up amazingly bright. The lead bullets i used had a long, bore riding section, easily embedded with 320 grit grinding compound. The bottoms of the grooves weren't bad at all, so I didn't put compound on the base of the bullet.
: When firing roughly 40 rounds of these polishing loads, with several cleanings, the tops of the lands came out smooth, with almost no pitting at all, yet the tube looked like a sewer pipe before attempting this.
: I like your fix, though. Re-lining the chamber with a piece of chromemoly - or a coating electroplated in it?
: There is another plating, that is as hard as a file, and grey in appearance. I had a replica Sharps action plated with this. It is almost impervious to the elements.
: Unfortunately, with this porcess, perhaps even the rifling would be plated. It doesn't seem to coat the letal, as much as fusing into the surface. Perhaps this stuff would work afterall. Only the parts submersed in the liquid are coated. It is called "Metaloy" and leaves a matt surface.


--------------------
Daryl


"a gun without hammers is like a Spaniel without ears" King George V


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empirevr
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Re: Pitting,once again..... [Re: DarylS]
      #64341 - 20/10/06 08:38 PM

Thanks for the info Daryl....

This is getting interesting,and confusing even........

So,where can you buy this 'metaloy'? is it specifically for gun barrels? how would one go about using it??

Also,given that this means filling the old pits,wont the rust be breeding underneath the fills??? how do you get around this?

Is it possible to chrome plate the bores i wonder? memories of my Baikal 12g with chrome bores......great old gun. Totally rust proof bores.

Ben-Daryl, welcome back! you went hunting,wasnt it?


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DarylS
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Re: Pitting,once again..... [Re: empirevr]
      #64351 - 21/10/06 01:47 AM

I was supposed to sit around camp to keep grizzlies away from the cook and her kids. It's a problem every year there. Due to a shortage of guides, I helpd out where and how I could by guiding a fellow in about the same decrepid physical condition as myself, so we managed quite well, although it was trying at times.
: Metaloy isn't something you can do yourself. It is a process done by some plating buisinesses.
: The rust must be cleaned out - which isn't a problem. There are products on the market for removal of rust and straight old gun solvent an 4-OUGHT steel wool on a brush works well enough.
: Most plating is a coating on top of the surface that will put a .001" to .003" surface film on the metal you are having plated. In this case, it will make the bore & chamber smaller in diameter. This may or may not be a good thing, depending on bore & chamber size size already. If the chamber and bore are already at the 'correct' size it is possible a .004" tighter chamber won't let you chamber a round and .004" tighter in the bore (1 thickness is .002" for expample X 2 = .004" total thickness) may mean special sizing dies or reducer dies for bullets. On the other hand, many of these guns had generous chambers and might benefit from such a coating. That is the mistery and can't be pre-judged unless the person you purchase from knows all the numbers you need to proceed with this. One must know what one is about here or one might get into trouble.

--------------------
Daryl


"a gun without hammers is like a Spaniel without ears" King George V

Edited by Daryl_S (21/10/06 01:51 AM)


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empirevr
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Re: Pitting,once again..... [Re: DarylS]
      #64355 - 21/10/06 05:30 AM

Thankyou Daryl

So as i thought, this is a job of sending the barrels away,or getting the gunsmith to do it? Dont much fancy doing it myself anyway!

Where does pitting matter most,on the lands or grooves???

Does this 'metaloy' fill the pits,or just coat everything thinly?

I pictured that one puts it down the barrel, it turns stiff/hard,then a die of the right bore is put through the barrel,and hey presto, no pits, fully lined clean bore......is this possible,impossible,or???

Thanks

Ben


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DarylS
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Re: Pitting,once again..... [Re: empirevr]
      #64363 - 21/10/06 08:12 AM

Not quite - Metaloy is a coating that is electroplated on the surface - all surfaces. Pitting is, of course, much worse in the chamber. It is most easily removed from the lands, as well as being polished from a chamber if not too deep.

--------------------
Daryl


"a gun without hammers is like a Spaniel without ears" King George V


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empirevr
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Reged: 03/09/06
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Re: Pitting,once again..... [Re: DarylS]
      #64374 - 21/10/06 12:05 PM

Ok thanks Daryl

So, there is no form of 'filler' that can be used on pitting? a barrel sleeve is the only option?(apart from re-barrel)

An ever-lasting or there-abouts filler or liner would be a superb option.

Sleeving and such are extreme options,but better than re-barreling.

Ideas?

Thanks

Ben


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DarylS
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Re: Pitting,once again..... [Re: empirevr]
      #64395 - 22/10/06 02:45 AM

Barrels for very small calibres and what's considered to be fairly low pressure shells only can be re-lined.
: Lining involves boring out the old rifling to a size that will allow insertion of the liner 'tube' that has the new bore and rifling inside. The barrels would have to be very large to do this and I don't think it would be practical in a BPE at all.
: Some coatings, like Danzak and Moly would invariably help with minor pitting to obtain good accuracy and clean shooting from a piece that isn't in too bad shape.
: A gentle polish with somthing like FLITZ or SOLVOL automotive polish will help about any slightly rough to bad barre. Even lighter is JB compound, put on a cloth patch and run up and down the bore with bore solvent, will bring up a nice shine if the bore isn't bad at all. Rougher bores need polishing/lapping with compounds, not out of the picture for the home hobbiest.
: Picture the sewer pipe modle 1871 Mauser I just did. The obre now shines, shows some minor pitting, but was dull, black and looking like vocanic rock when I got it. It doens't even lead now, with full power loads using either Lyman's BP lube with Black Powder or Lyman's Moly lube with smokeless powder (both stick lubes for lube sizers).

--------------------
Daryl


"a gun without hammers is like a Spaniel without ears" King George V


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empirevr
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Re: Pitting,once again..... [Re: DarylS]
      #64409 - 22/10/06 08:58 AM

Thanks Daryl

So,barrel reaming is out of the question for a bpe really.

So,in other words,the pits are coated,yet not filled to any noticable extent,correct? Apart from use of some forms of ammo,there is no way to fill the pits with a hardened substance?(as one would have a tooth filled)

If the gun shoots well,the only thing to worry about is ceasing the pitting/rust i.e. by coating it,and using it as is,or do the pits cause other problems permanently regardless of such works?

The Mauser you did, is this substance you used permanently fixed(i.e. like the tooth-filling example) or does it come loose,or even secrete rust underneath??

Thankyou kindly.

Ben


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DarylS
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Re: Pitting,once again..... [Re: empirevr]
      #64441 - 23/10/06 01:07 AM

I wound't say it is out of the question. A set of .450 barrels could conceivably be reamed out to .475 or .50 and re-rifled if there is enough meat in the barrels.
: I know of no substance that could be put in to fill the pitting evenly with the bore & then harden, unless Danzac will do that to sme extent. You can do a search with goggle for info on that stuff.
: I think perhpas you have the wrong idea about pitting. Mild pitting isn't too bad and can be polished to where it does no harm. The worse pitting is in the chambers, where the case can expand into them and not eject.
: The Mauser I did, was merely firelapped smooth due to the grinding compound imbedded on the bore-riding nose of the lead bullets I shot from it. It is a simple process. If both grooves and lands have pitting, then the entire bullet is imbedded in compound. There are kits available in the States for doing this with modern rifles and old ones alike.
: The coating I did on the Sharps, the Metaloy, becomes one with the surface of the metal with some penetration of that surface. Nothing can get under it, but the surface must be perfectly clean or it won't work.

--------------------
Daryl


"a gun without hammers is like a Spaniel without ears" King George V


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empirevr
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Re: Pitting,once again..... [Re: DarylS]
      #64445 - 23/10/06 02:39 AM

Thanks again Daryl.

So, worst pitting is in the chambers,and what of the muzzle? if pitting is very bad,is there risk of a barrel blowing? or are such barrels too thick for this to happen?

1mmx1mm pits for example,are able to be polished out then i take it? Does this polishing involve much removal of metal???

By polishing the lands, does this not effect the caliber size?

Danzac,hmm, interesting.........could be the answer.

Ben




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DarylS
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Re: Pitting,once again..... [Re: empirevr]
      #64456 - 23/10/06 06:17 AM

: Pitting, it's location and how it will effect shooting, safety, etc is something someone with experience must see to judge it's traits. It is virtually impossible to attempt to explain it here, over the phone, or however.
: Pitting is rarely a dangerous thing, but can be. In Damascus barrels it can be very bad indeed as what looks like a very tiny tiny hole, may run angled, through the welds almost to the outside surface. If the bottoms of the pits are easily visible, and a scribe or dental tool can mark or feel solid steel underneath, they probably aren't a safety concern. 1 mm deep pits are 1/25th inch deep which is deeper than 1/32nd" or 1/2 of 1/16". I'd call that deep, but perception is a personal thing. To me, anything deeper than about .020" is deep.
: Pitting is something that is common in poorly maintained guns. It matters not that the primers used were corrosive. If fired and well taken care of by prompt cleaning by proper methods for the priming & powders used, the bores would be bright and shiny as many are. BTW- modern oil based solvents are not suitable for cleaning fouling left by corrosive primers. A water based solvent must be used. I have seen too many properly taken care of guns to accept a broad statement that pitting in 100 year old or older guns is unavoidable. Many have it, and many of those can be salvaged, but by someone who knows what they are doing. Many don't have any pitting at all. My own Sharps .50/70 barrel from a model 1859 has no pitting on the outside of the barrel. It was re-lined by Sharps in 1867 or 1868 and chambered to .50/70. It was only a tiny bit rough, but is bright and shiny, originally when I bought it, had nothing deeper than .001" or .002". .002 is only 5% of 1 mm. This bore polished up almost like a new barrel would appear. Polishing the lands & grooves should not remove enough metal to change calibre. If that much material needs to be removed, then a re-bore may be necessary. I know of no one who does this to doubles, but I suppose H&H most certainly will. Be aware, that if done in Engand, they'll re-proof the gun. Perhaps that's a very good thing.
: Buyer beware. I would be most hesitant in buying a gun that has pits on the outside as that was the easiest place on the gun to take care of. That would mean it was totaly negleated. The H&H you pictured or sent to me, was well overpriced in my opinion as it was very poorly taken care of and I believe poorly refurbished.
: Value is whatever you can get for something, I guess and one man's price may be well below what someone else is willing to pay - obviously.

--------------------
Daryl


"a gun without hammers is like a Spaniel without ears" King George V


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empirevr
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Re: Pitting,once again..... [Re: DarylS]
      #64460 - 23/10/06 06:53 AM

Thankyou for that Daryl.

Some great information there.

So,it seems Damascus barrels are quite a worry if there are pits in the equation!!!

Most of the guns on offer have come from India,and it seems the humidity there has caused much rusting damage.

The Holland you mention i have avoided totally,as i can see the damage is severe.

Boring out to another cal. i think of as out of the line of reason with regards to a rifle of this type. Better to avoid that gun,and continue looking for another.

Thanks for the great info.

Ben


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500Nitro
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Re: Pitting,once again..... [Re: empirevr]
      #64462 - 23/10/06 06:57 AM

empirevr

Pitting in the chambers is very bad IMHO -and can cause problems with Extraction of cases, Ruptures etc.

BP Guns with Small pits / alot of wear, especially big bores are generally not a susceptable as small bores.

Pits in BP guns do get filled up with lead and BP residue or can be filled up with lead to make them look smoother. That is why it is best to REALLY clean a BP guns barrels to get all the crap out so you can see it's true state.

I don't worry about "FROSTING" or light pitting as this was often caused by the firing of cartridges.

I am more concerned if the rifling is seriously worn in the last half of the barrel - I have noticed that guns that are worn in the first half but have good 2nd half still shoot.

Also be concerned if the mussle / crown area is pitted.

Just my HO.

500 Nitro


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