.50 BMG strange bullets (Kynoch ?)

I wonder if someone can help me with these?
All bullets are red. That colour remains even after cleaning and even remains after the red tip vanish.
First one has traces of black paint in the tip (not seen in this picture), as the one in the right.
The one in centre as a red tip.
All have purple circle round primer.
The 1st has only one knurled ring, the second (tracer?) and the third (AP?) have 3 knurled rings.

I have never seen all red bullets like these in .50 BMG. I guess K stands for Kynoch, and 79, 75 for 1979, 1975, probability the black tips are for AP and red for tracer, but I’ve never seen the red bullets so I am not sure about these ones.



I don’t think the red color is unusual. A lot depends on the alloy used and where the cartridges were stored. Under certain conditions, cases and bullets can turn a dark brown or deep red. Or, they may turn almost black.

I have two Cal .50 cartridges that show almost the same colors as yours.

One way to “age” a cartridge that has been cleaned and polished is to expose it to certain conditions such as high humidity, city smog, or smoke. Even bright direct sunlight can cause brass and copper to change color over a fairly short time.

I’ve read that kings in ancient times would have their prized bronze sculptures hand rubbed by slaves for days, weeks, and months on end in order to give them a velvety patina. If you carry a copper cartridge in your pocket and handle it daily for only a minute or two it will take on that same glow. But, I’m rambling.


Yes, that could be oxidation or chemical contamination of some sort, that was my first assumption but I found very strange the fact that the red color is so well fixed that it cant be removed with brass cleaner (the red tip in ordinary pain came out quite easily).
A few minutes ago I dissembled one cartridge and removed the bullet. In fact, the bullet section that was inserted in the cartridge case is not red at all, so the color in the exposed surface is probably due to some chemical process that affected the brass that way.