Tarnished Bullets

[gunsandgunsmithing]

I've often wondered what age and/or oxidation can do to bullets. If you've ever worked with new copper tubing vs. old copper tubing, then you know the difference is not small, but more like night and day.
This is with copper tubing that has only been stressed by just being coiled on a shelf for a few years, in a shop.

Bullet jackets are under a great deal of stress once the core is seated and the bullet gets pointed up. I would only guess that, that would compound the hardening effect of stress many times that of being coiled on a shelf. I realize the annealing is likely different and the alloy can vary a little.

I've never shot, that I can remember, bullets that were severely oxidized /tarnished, through a true BR barrel, or other rifle that could prove one way or the other. Oh, I've shot custom bullets that were somewhat tarnished from rifles that should. But never any that were severly discolored or oxidized. Where is the line? I'm not claiming either way, but asking..how do they shoot.

 

[370bc]

The line that I make myself is that if they are tarnished, the get put in the vibratory cleaner for about for 45 minutes. I tried to pull some old 55 grain Nosler ballistic tips that I had loaded a long time ago while not wearing the rubber gloves that i use today. I broke my kinetic bullet puller, trying to pull the bullets, the oxidation was so bad. I could imagine the increase in velocity and pressure compared to a load w/o any oxidation present. Back then I did not anneal my cases, either. I've made big improvements since those days.

 

[gunsandgunsmithing]

The line that I make myself is that if they are tarnished, the get put in the vibratory cleaner for about for 45 minutes. I tried to pull some old 55 grain Nosler ballistic tips that I had loaded a long time ago while not wearing the rubber gloves that i use today. I broke my kinetic bullet puller, trying to pull the bullets, the oxidation was so bad. I could imagine the increase in velocity and pressure compared to a load w/o any oxidation present. Back then I did not anneal my cases, either. I've made big improvements since those days.

If they shoot well, I guess that answers my question...Thank you!

The tarnish I'm talking about is more than skin deep. Or at least I think it may be.

 

[gunsandgunsmithing]

I guess I'd draw the line Mike, when the tarnishment (if there is such a word!) is heavy enough to pit, or otherwise damage the jacket. I suppose those with light pitting could be cleaned and used for foulers, or sighters, but I wouldn't use them in competition. Why put "iffy" bullets through a limited life, precision barrel, when you can use known quality, brandy-new ones?

Chris Mitchell

Thank Chris. I agree.

 

[carlsbad]

Mike,
I don't have much experience with copper but a lot with other metals and it doesn't make sense to me that the copper would change metalurgically sitting on the shelf at room temperature. I would think it more likely that old copper tubing was manufactured differently than new. Old tubing was always that way.

As for tarnish, I think it is skin deep. It is caused by oxidation of the surface layer. The green patina is accompanied by pitting and material erosion and I would avoid green bullets. The darkened copper caused by a thin layer of copper oxide would possibly affect neck tension more than anything.

But I don't claim to be a copper expert.

 

[gunsandgunsmithing]

Mike,
I don't have much experience with copper but a lot with other metals and it doesn't make sense to me that the copper would change metalurgically sitting on the shelf at room temperature. I would think it more likely that old copper tubing was manufactured differently than new. Old tubing was always that way.

As for tarnish, I think it is skin deep. It is caused by oxidation of the surface layer. The green patina is accompanied by pitting and material erosion and I would avoid green bullets. The darkened copper caused by a thin layer of copper oxide would possibly affect neck tension more than anything.

But I don't claim to be a copper expert.

Me either Jerry. Copper tubing is generally 99.9% pure copper. No doubt in my mind that it hardens with time. It goes from very malleable to unworkable.

 

[snert]

Just cause she is dirty doesn't make her bad to the core....or something like that!