brass color

[leadbutt]

I was citric washing some 9mm brass and I seen that a few of the cases started looking like they were copper. Do they make brass plated copper cartridges? Whats going on? Thanks in advance.

L. Bottoms

[acoop101]

Check then with a magnet, there are companies making brass plated steel.

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[Mauser48]

It's the way the citric acid reacts with heavy tarnsish. Same thing happened to me when I tumbled some black 223 brass from pendleton. Also, I tumbled some 257 brass that had some heavy brown spots on it. When I took it out, the brown spots were a slight pink. It's fine.

[leadbutt]

Ok so what im getting is its ok to fire just don't enter them in any beauty pageant?

[rond]

Brass is a mix of copper and zinc, maybe some have more copper in them?

[Bent Ramrod]

The citric acid is reacting with the metallic zinc in preference to the less active copper, leaving the copper surface (and color) behind. It shouldn't hurt the use of the cases, and the copper color should polish out.

However, you should use only enough citric acid to dissolve and complex the copper and zinc oxidation (i.e., tarnish) on the surface. Try cutting the concentration of your solution by 10-25% and see if the condition goes away. Shorter contact time might help as well.

[paul edward]

The copper color is, in fact, copper. Either your citric solution is too strong or you are leaving the cases in too long. It only takes a minute or two. It helps to first wash the cases to get rid of oil and grease that hold dirt, sand and carbon grit. Effective cleaners are hot water with tri-sodium phosphate (TSP) or dish soap. Clean is good.