Results 21 to 30 of 107
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18-06-2020, 13:05 #21
Re: Mauser Werke A.G. Oberndorf ES340B .22LR - shot out or dirty?
It's a common statement that people make, copper brushes wearing a barrel.
I personally don't believe it's possible to wear barrel steel with a copper brush.
If you make a saw blade from pure copper, and try to saw the end of a rifle barrel off with it, you will just remove the blue. You can saw on it till the copper gets hot and melts, it cannot cut barrel steel.
What can wear rifling is the copper brush with something like abrasive paste, then it's the paste that's hard and does the wearing, not the copper bristles.
I understand that copper bullets wear a barrel out, and maybe the assumption is made from there that because bullets are copper, and brushes are copper, that copper brushes wear barrel steel.
The wear mechanism of copper bullets is not equivalent to copper brushes.
I'm not clear on what exactly wears a barrel, but I think that where it occurs quickest is a clue. The throat goes first. General opinion is that this is due to heat from the powder oxidising the steel. Hence the term "barrel-burner" for some calibers.
Wear is more noticeable at the muzzle, where bullet speed is at maximum.
The second clue is where the wear isn't. It's not uniform along the length of rifling.
A bullet travels down the rifling. If copper alone wears steel, the bullet would in every case without exception wear the rifling down evenly down the barrel length once past the throat.
That is not what happens, so some other mechanism is in effect.
Maybe something to due with the primer and steel oxidation residue, small particles embedded in the copper as the bullet travels, abrading the steel, more abrasion where speed is higher.
Or maybe I'm completely wrong, and copper on it's own does wear barrel steel.
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18-06-2020, 13:18 #22
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Re: Mauser Werke A.G. Oberndorf ES340B .22LR - shot out or dirty?
Or maybe I'm completely wrong, and copper on it's own does wear barrel steel.
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no ways, would take some convincing for me to believe that.
Barrels get burnt and oxidized and abraded from the chamber forward, the forward is just because it takes longer to wear the further the barrel gets from the ignition.All the barrels I thought were worn at crown turned out to be heavily coated, fouled with lead/copper deposits.
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18-06-2020, 14:59 #23
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Re: Mauser Werke A.G. Oberndorf ES340B .22LR - shot out or dirty?
Some copper brushes are made from an alloy, I think copper-bromium or copperfloride or something similar. That is the stuff used to cut diamonds. It can most definitely wear out a barrel.
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18-06-2020, 15:19 #24
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Re: Mauser Werke A.G. Oberndorf ES340B .22LR - shot out or dirty?
All "copper" brushes for rifles are made from phosphor-bronze. It is an alloy of copper, tin and phosphorous. It is harder than lead and copper, but softer than iron and steel. The idea is to be able to brush out lead and copper without harming barrel steel. You cause more harm using ammonia-based cleaners than bronze brushes.
Where it could be harmful is when used in conjunction with abrasive cleaners. But then it would be just as harmfull as using nylon brushes.
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18-06-2020, 15:19 #25
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Re: Mauser Werke A.G. Oberndorf ES340B .22LR - shot out or dirty?
Far as I know the copper wire brushes were / are -- PHOSPHOR-Bronze
Some answers here
https://sandersonmacleod.com/firearm-cleaning-brushes/
https://otistec.com/bloghow-to-choose-the-best-bore-brush-for-the-job/
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18-06-2020, 16:26 #26
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Re: Mauser Werke A.G. Oberndorf ES340B .22LR - shot out or dirty?
I have been wondering about the use of sodium hydroxide (caustic soda) for this cleaning purpose? NaOH will not react with steel, but it does react with a lot of other gunk. A friend of mine used braai grid cleaner which is a mix of NaOH and detergents to clean a really dirty barrel. He said it worked like a bomb. He then just hosed the barrel out with water after soaking.
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18-06-2020, 16:39 #27
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18-06-2020, 17:41 #28
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Re: Mauser Werke A.G. Oberndorf ES340B .22LR - shot out or dirty?
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Kind of stuff I was referring to in post # 1 - (I am now getting desperate, I am using various degrees of desperation potions (I will not open that can of debate worms, lets just say some people may feint)
I do a lot of that kind of thing.
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18-06-2020, 19:06 #29
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Re: Mauser Werke A.G. Oberndorf ES340B .22LR - shot out or dirty?
Then bring on the Draino - if you can find some... after Trump suggested its use to treat Covid
The stuff my friend used was from the catering suppliers - Hygiene heavy duty base oven and grill cleaner.
In the lab, if there was something that didn't come clean, we would try either strong organic solvents, strong acids, strong bases, or oxidizing agents, and any combination of heating and cooling.
If it is lead fouling, then what is the melting temperature of lead, and can you get to that temperature in a controlled manner without disturbing the metallurgical properties of the barrel?
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18-06-2020, 19:41 #30
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Re: Mauser Werke A.G. Oberndorf ES340B .22LR - shot out or dirty?
Oven cleaner works a treat as a once off, rescue a lost case.
Just remove stock and tape rifle end to end before starting.
I am going to use oven cleaner tomorrow on the .22
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