Pitted Barrel Project

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Scota@4570

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Mad Monk (Bill Knight) is the foremost expert on the subject of ML propellants. On the American Long Rifle Forum he posted:

"I just dropped in to see what has been going on.
To answer your question.
Pyrodex uses 17 parts of Potassium Perchlorate as part of the oxidizer system. Powder combustion converts that potassium perchlorate into potassium chloride. Minute crystals scattered over the surfaces of the bore. Given the right range of relative humidity each of the tiny crystals becomes an electrolytic corrosion cell on the surface of the metal. This "micro-pitting" happens very quickly. It makes the bore's surfaces look dull. Under magnification they are seen to be little pits in the metal. Most shooters who used, or use, Pyrodex find it necessary to frequently check the bore during storage. Once you get surface pitting of the metal it is difficult to insure no traces of the chloride have entered the porous metal in the pits.

This chloride pit corrosion was one of the driving forces behind the development of the 777 powder. It is free of any chlorides and will not pit corrode the bore. When the in-line crowd went to plastic sabot carrying pistol bullets the minute crystals of chloride left by Pyrodex made reloading without cleaning difficult at best. So getting rid of the potassium perchlorate became a must in the 777 development project. While the 777 is a bit more difficult to ignite, compared to Pyrode, it is a far better powder. More powerful and very clean burning. Being more powerful you can use less of it in a load. It's post combustion residue, as with black powder, may cause light surface rusting it will not pit corrode the bore.

Bill K."
 

Loyalist Dave

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I would lap it first and see how it shot.
Agreed,
but first the Scotch Bright, aka "green scrubbies" aka "magic moss", does a good job, but I'd plug the nipple, and fill the barrel with Evaporust, and let it sit 36 hours...THEN dump it and rinse it, and then as suggested, lap the bore a bit. You might find that if you can remove the sharpness of the craters a bit you won't shred patches. You may also find that switched to casting some Lee brand REAL bullets, which will forgive the pitting, brings that very short rifle "back from the edge".

Mr. Hoyt can tell you if he can ream the bore or not, if the above fails. You might find that having the lands reduced and then having the grooves "refreshed" to make it a .52 will work, or if not ...have it made into a .530 smoothbore if that's as large as he feels it can be made and be safe. Consider that our 28 gauge .54-.55 caliber smooth barrels are just an arbitrary standard set "back in the day". Lee makes both .500 round ball and .520 round ball molds.

BTW...a smooth, .526 bore is a 32 gauge. I wonder if a .520 bare ball would "just fit" inside a barrel with such a diameter ??? ;)

LD
 

Okie Hog

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This chloride pit corrosion was one of the driving forces behind the development of the 777 powder. It is free of any chlorides and will not pit corrode the bore. When the in-line crowd went to plastic sabot carrying pistol bullets the minute crystals of chloride left by Pyrodex made reloading without cleaning difficult at best. So getting rid of the potassium perchlorate became a must in the 777 development project.
Yep, Bill Knight knows lots of stuff. But Bill Knight is dead wrong on Triple Seven. Triple Seven contains a huge dose of potassium perchlorate.

All the black powder substitutes except for BH 209 contain potassium perchlorate.


https://www.hodgdon.com/wp-content/uploads/2018/08/2018-tripleseven-sds-new.pdf
 
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Dphar1950

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I shoot only black now but I am sure I started using pydrodex as soon as it came out but don't remember the year. Later a local guy opened a frontier shop that stocked black and I went back to it. I leave my rifle loaded all season if I don't get a deer, back in my early days and when I shot pydrodex I loaded my gun in the morning before I went hunting and shot it empty every evening and gave it a good cleaning. Consequently I never had a problem with pydrodex eating up my barrel but I have see some horrible examples of what it can do.

Like this one;

View attachment 21642
Look at it with 10X magnification. I have never seen a Pdex barrel that did not show some form of pitting. On hot tank blued barrels the first clue is the blue is removed from the bore. Most people don't even know what they are seeing. AND there may be no sign of red rust.
Dan
 

trent/OH

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I'm glad to see a post on the White Lightning carbine. I bought one for my wife for her first rifle in September at Friendship. She towers over the world at 5'0" and needs a small rifle. She immediately shot much better than using a CVA Bobcat (although a 44" range rod is a bit much for the 18 1/2" barrel). Then my niece-in-law-to-be shot it at the New Years Day shoot at Friendship, and was in the black offhand on her second shot (2nd time ever shooting). then my nephew used it to split a playing card!

I was very glad to see a down-bore picture of the breech of the rifle. Now I see the Patent Breech and about how large it is. Thus I can plan my cleaning better. A .22 brush seems to get into the Patent and remove some ick.

So, thank you for starting the topic, and for the photo. It has started a lively discussion and proven itself to be a valuable discussion starter.
 
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I hate to hijack back to the original topic, but I recently had Robert Hoyt rebore a T/C Tree Hawk from .50 to .54. It was roached in the original caliber and a patch shredder. There was sufficient metal to allow the increase in bore size and rifling. The Tree Hawk is in the same barrel size range as your White Mountain. The outside diameter of the round barrel is 15/16ths. The round section of yours should be equivalent.

Pete Davis
 

M. De Land

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This gun was a "gift" from my uncle to my brother that he acquired a number of years ago. We got it, scrubbed it, lubed it, and it sat happily in a temperature controlled environment until Thanksgiving. Odds are that gun never saw a cleaning patch til we got ahold of it, so theres no telling what powder was used and for how long the gunk of that powder had been working on the inside of that barrel.

RM
Actually if the rifling is still strong I would pull the breech plug and lap the bore. You will not remove the pits but will take the patch snag off from all but the very deepest. The crown will be the most important in that it needs to be pit free and evenly chamfered.
All rifling has to do is spin the patch ball without tearing the patch. If it will do that it will be accurate as it ever was before. Pitting usually does foul faster but even that can be managed if care is taken between shots with swabbing or dry brushing.
It really bugs me to have pits in a bore which only happens with used guns in my case but I have learned over the years of gun building and repair that a rifles bore does not have to be pristine to be accurate.
 

Cobra6

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I understand re-boring and new liners but how do they refresh barrels? Seems to me that I've read some time ago that it involves sending down a "reamer" to recut the original rifling. If that's the process, can they increase the cut on the grooves and leave the bore size the same? Time to call Hoyt.

Cobra 6
 

SDSmlf

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I understand re-boring and new liners but how do they refresh barrels? Seems to me that I've read some time ago that it involves sending down a "reamer" to recut the original rifling. If that's the process, can they increase the cut on the grooves and leave the bore size the same? Time to call Hoyt.

Cobra 6
In the simplest terms, refreshing basically uses a tool to follow and cleanup the original rifling, resulting in a slightly larger diameter bore. Possible results could require a custom roundball mold. Bobby Hoyt is a subject matter expert and would be a great person to talk to. Call him.
 

Cobra6

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TKS...SDSmlf and Carbon 6. Carbon 6, I bet you know that Carbon has 6 Protons and 6 Neutrons? Retired chemistry teacher.

Cobra 6
 

Dphar1950

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You cast a fairly long lead piece, a lap if you will, in the barrel to give a good representation of the rifling. Then one groove impressions (its the raised portion of the rifling on the lap, I call it a lap since its identical to the casting used to lap a barrel) is cut down deep enough to put a multi-toothed hardened steel cutter that fits the slot securely and matches the grooves in the barrel. It is raised high enough to cut the groove deeper with pieces of onion skin used as shims. Lube it with cutting oil or even lard (which will tend to trap the cuttings) and put it in the barrel and work it back and forth. When it ceases to cut that groove rotate to the next groove and repeat. Brush clean and re-lube the cutter every pass. When ALL the grooves are cut to that depth wipe the bore dry, DRY like with denatured alcohol so there is NOTHING in the bore. Look at the grooves carefully. It they are all nice and clean the grooves are done. But this is unlikely if its pitted very badly. So put in another shim of paper and repeat the process. If the bore is pitted it will take some time. When the grooves are all good melt the lap down and cast another one in the barrel and put a cutter in the groove in the lap that represents the lands. Cut the lands down until they are all clean. Hopefully the grooves will end up .008-.010" deep. This can be done with a wooden rod but a steel rod with a BEARING HANDLE is best and it must have 2-4 flats filed on it to fix the "lap". Heat both the steel rod barrel before casting. The lap needs to be at 6" long since its the "rifling guide". And unlike a lap cast for lapping a harder alloy may be used on this which, if containing 1 part tin to 20-30 parts lead will make a smoother and more accurate casting in most cases. I used to have a book on with a section on freshing I can't find it in looking through 5 book cases here and in the shop.
I think what you need is here but not sure since my copy now over 50 years old I cannot find. https://www.ebay.com/itm/How-to-Build-Muzzle-Loading-Rifle-Target-Pistol-Powder-Horn-Cowher/153823923072?hash=item23d09ecb80:g:0fwAAOSwfiRePI2U
My advice is to send it to someone and have rerifled. Freshing will likely produce a bore size that will require a odd sized mould to get a proper ball fit.
 

Cobra6

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Dpart1950

Thanks for the advice. However, I'm a "babe in the woods" when trying to understand the process of "casting a long lead piece" for this process. I have a 54 Cal TC Hawken that is all over the place on target. That is at 25 yds, so you see my concern. I'm guilty of this since I shot the Hawken and not really cleaning it correctly between military assignments. I shot the 54 Cal off and on for 27 years [between assignments] and finally retrieved it from my father-laws place, neglected it again for 10 years and now trying to regain some respect with Thompson Center. Anyway....I think you give good advice when stating that a re-rifle is the best solution. Presently, the 530 round ball with a .012 patch fits very tight, however after refreshing a .535 ball [after refresh] would work fine? Stay with me on this.

Cobra 6
 

SDSmlf

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Dpart1950

Thanks for the advice. However, I'm a "babe in the woods" when trying to understand the process of "casting a long lead piece" for this process. I have a 54 Cal TC Hawken that is all over the place on target. That is at 25 yds, so you see my concern. I'm guilty of this since I shot the Hawken and not really cleaning it correctly between military assignments. I shot the 54 Cal off and on for 27 years [between assignments] and finally retrieved it from my father-laws place, neglected it again for 10 years and now trying to regain some respect with Thompson Center. Anyway....I think you give good advice when stating that a re-rifle is the best solution. Presently, the 530 round ball with a .012 patch fits very tight, however after refreshing a .535 ball [after refresh] would work fine? Stay with me on this.

Cobra 6
If your bore is rough from neglect, you will likely go up a couple of ‘calibers’ before refreshing will clean it up. A rough 54 caliber bore could possibly go to 55 or 56 caliber and not be fully cleaned up. Would take more than a .535 ball to shoot accurately.

I have both flint and percussion TC barrels (with one inch flats) that were rebored to 58 caliber by Bobby Hoyt and they are great shooters. 1-60 twist with radius bottom grooves.
 

nkbj

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TC fifties have such shallow grooves that they will often clean up with very little increase in caliber, which offers the opportunity to design a bore.
 

Dphar1950

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Dpart1950

Thanks for the advice. However, I'm a "babe in the woods" when trying to understand the process of "casting a long lead piece" for this process. I have a 54 Cal TC Hawken that is all over the place on target. That is at 25 yds, so you see my concern. I'm guilty of this since I shot the Hawken and not really cleaning it correctly between military assignments. I shot the 54 Cal off and on for 27 years [between assignments] and finally retrieved it from my father-laws place, neglected it again for 10 years and now trying to regain some respect with Thompson Center. Anyway....I think you give good advice when stating that a re-rifle is the best solution. Presently, the 530 round ball with a .012 patch fits very tight, however after refreshing a .535 ball [after refresh] would work fine? Stay with me on this.

Cobra 6
You should be able to get a replacement barrel for it.
 
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