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Joined: Nov 2007
Posts: 207
Campfire Member
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Campfire Member
Joined: Nov 2007
Posts: 207 |
Do all Ramshot, Alliant & Norma powders burn cleanly, or just TAC, RL-15 & 204? Which of the slower burning powders (Hunter, RL-19, H4350, H4381SC, & N160) also resist carbon and copper fouling?
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Joined: Dec 2000
Posts: 29,348
Campfire Ranger
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Campfire Ranger
Joined: Dec 2000
Posts: 29,348 |
I don't know the relative percentages of the following causes of bore fouling (and this ignorance bugs me!). I assume that like everything else, they vary a lot.
� vapor-flashing of copper from the base of the bullet onto the steel of the bore
� friction, often intensified by extra-rough tops of the lands (common when the barrel-maker didn't ream the bore smooth before he rifled it)
� chemical make-up of the powder (temperature of the high-pressure gas)
"Good enough" isn't.
Always take your responsibilities seriously but never yourself.
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Joined: Aug 2006
Posts: 99
Campfire Greenhorn
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Campfire Greenhorn
Joined: Aug 2006
Posts: 99 |
Yes, there are powders containing decoppering agents. I cannot say which type of powder is more or less effective. But Bofors/Alliant powders like Re7, 10x, 15, 19, 22, 25 and the Norma powders seem to be very effective. Among others, Bofors patent CA2475497 (Canadien patent) describes the chemical background. There are a lot more patents regarding decoppering agents, use www.google.com/patents "decoppering agent" to browse for information.
"A stupid man's report of what a clever man says can never be accurate, because he unconsciously translates what he hears into something he can understand." Bertrand Russell
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Joined: Nov 2007
Posts: 207
Campfire Member
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Campfire Member
Joined: Nov 2007
Posts: 207 |
Thanks for the patent number. There is an informative 3-page description in the Canadian patent database ( http://patents.ic.gc.ca/cipo/cpd/en/patent/2475497/summary.html?query=2475497&start=1&num=50 ). Apparently, tin and bismuth are added to the powder as a decoppering agents. The patent description states that copper fouling became a problem after lead was discontinued as a primer ingredient. In the past, lead from primers kept copper from fouling barrels. It's interesting that Bofors of Sweden owns the rights to the Alliant Reloder powders. This is similar to the relationship between Australian Defence Industries (ADI) and Hodgdon.
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Joined: May 2005
Posts: 16,554
Campfire Ranger
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Campfire Ranger
Joined: May 2005
Posts: 16,554 |
Fascinating, what's old is new again: In the period immediately following World War I, the question of metal fouling had not been solved, and the rifle shooter was constantly confronted with trouble from this source.
The French, whose artillery we used very largely in that war, were known to place metallic tinfoil in with the powder charges used for field guns, in order to prevent the depositing of copper fouling from the metal of the rotating bands on the shell.
After the end of that war, the du Pont organization obtained patents on the idea of incorporating finely powdered metallic tin in the colloid form which the gunpowder was made. Popular du Pont powders of that day were Nos. 15, 17, etc. When tin was added to the composition of one of these powders, the figure � was added to the number designating the powder. Thus powders No. 15�, No. 17�, etc. were the same as Nos. 15, 17, etc., except that they contained a certain percentage of tin. The first of these powders that we tried in a military loading was No. 17�, which was used in the National Match ammunition of 1921. and thereabouts. This was said to contain 4% of metallic tin. It did eliminate the old metal fouling, but at the same time it introduced another kind, though a less troublesome one. This was tin fouling, which took the shape of a dark smoky looking deposit inside the bore of the rifle near the muzzle. On close examination, this appeared to consist of minute globules of metallic tin adhering to the surface. Evidently the tin in the powder vaporized under the terrific heat of the explosion, then condensed on the comparatively cool surface near the muzzle, after the gas had also been cooled somewhat by the expansion from its first high pressure to a pressure only perhaps one tenth of the peak figure.
On cleaning a gun so afflicted, it would be found that the cloth patch would stick rather tightly on the rough surface where the tin had been deposited. Once this fouling had occurred, the only remedy was to scratch it out with a stiff wire brush, which removed it quickly and with little difficulty.
As a remedy, the percentage of tin used was reduced, first to 2�%, then to 2%, and later to 1� percent or less. Julian S. Hatcher, Hatcher's Notebook, at 329-330 (3rd ed. 2d printing 1966) Apparently the new alloy with its lower melting point solved the tin fouling problem, 42%Sn/58%Bi melting at 138�C (from the patent abstract) and tin at 232�C. Or perhaps the alloy has less "stick-sion."
The key elements in human thinking are not numbers but labels of fuzzy sets. -- L. Zadeh
Which explains a lot.
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Joined: Nov 2007
Posts: 207
Campfire Member
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Campfire Member
Joined: Nov 2007
Posts: 207 |
Some of you are probably bored with this thread but I�d like to post the results of my correspondence with Western Powders, the manufacturer of Ramshot powders.
Per Western Powders: �There are currently no Ramshot powders with anti copper agents.�
I was emailed a copy of the Ramshot MSDS. Send a private note to me if you want me to forward a copy to you. The MSDS does not mention any traditional decoppering agents, such as tin or bismuth. Perhaps other means of ensuring a clean burn are used.
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Joined: Jul 2001
Posts: 60,149 Likes: 11
Campfire Kahuna
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Campfire Kahuna
Joined: Jul 2001
Posts: 60,149 Likes: 11 |
Hmm. I was personally told there were several years ago. Maybe they have changed the formula. This requires further investigation!
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
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Joined: Aug 2003
Posts: 17,491
Campfire Ranger
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Campfire Ranger
Joined: Aug 2003
Posts: 17,491 |
I suppose there could be reasons either way for not promoting as well as denying certain intentionally formulated properties. If you say it has them, some people may, due to other factors, not see the result, while other folks might become needlessly concerned with the theoretical possibilities of case breakdown - since brass contains copper. Either angle is not good for promoting sales. Sometimes people focus too much on peripheral (often theoretical) "facts" rather than the real facts.
Sometimes, the air you 'let in'matters less than the air you 'let out'.
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Joined: Jul 2001
Posts: 60,149 Likes: 11
Campfire Kahuna
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Campfire Kahuna
Joined: Jul 2001
Posts: 60,149 Likes: 11 |
Who knows? The person who told me is VERY high up in the company, and still there, so I will just ask again. In fact, it was his statement that got me investigating such agents in other powders.
That said, I suspect that clean burning is more important in maintaning a clean barrel. Smokeless powder residue is quite abrasive, and so the cleaner the powder burns the less jacket material is likely to be worn from the bullet. Combine that with a nicely smooth bore, and copper fouling is pretty minimal anyway, in my experience. Ultra Coat the bore and things get even better.
Last edited by Mule Deer; 12/20/07.
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
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Joined: Jan 2001
Posts: 28,388 Likes: 1
Campfire Ranger
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Campfire Ranger
Joined: Jan 2001
Posts: 28,388 Likes: 1 |
...Sometimes people focus too much on peripheral (often theoretical) "facts" rather than the real facts. "Sometimes"? I thought that was the raison d'etre and fundamental modus operandi of all internet forums?! 
Gunnery, gunnery, gunnery.
Hit the target, all else is twaddle!
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Joined: Nov 2007
Posts: 207
Campfire Member
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Campfire Member
Joined: Nov 2007
Posts: 207 |
Yukoner, I believe that we have finally uncovered the reason why Norma 204 powder reduces copper fouling. I've just received a N204 MSDS from Black Hills Shooters Supply, a Norma distributor. Here are the listed ingredients: � Nitrocellulose � Nitroglycerine � Centralite I � Bismuth (III) oxide Note the last item. Per Chemistry Zone ( http://chemistryzone.blogspot.com/2007/12/smokeless-powder.html ): �bismuth compounds are favored as copper dissolves in molten bismuth, forming brittle and easily removable alloy.� I'm no expert on these topics. An MSDS can be found on most smokeless powder websites. I believe that only hazardous materials need to be listed, so it is possible that some companies neglect to list decoppering agents. I remain surprised, however, that the Alliant MSDS omits nitrocellulose as an ingredient in its double-base Reloder 7, 15, 19 & 22 powders.
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Joined: Feb 2001
Posts: 4,085
Campfire Tracker
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OP
Campfire Tracker
Joined: Feb 2001
Posts: 4,085 |
I have just read your post about the Bismuth (III) Oxide. Very interesting, and perhaps the reason for the very distinctive results observed using N204.
Appreciate all of you who have posted about this.
Ted
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