Primer material

Am cataloging some new made pistol cartridges and notice a big difference in the color of Brass primers. Was wondering if anyone knows what brass formulas different manufactures now use for primer cups. Many rimfire cartridge cases over the years use the standard “cartridge brass” ie: 70-30 copper-zinc mixture. Others have used 68-32 and 65-35 mixture to make what is commonly called Red Brass. Several of the primers on the catrridges cataloged are more red than others. Am not confusing primer seal with the primer material. Don’t need any smart mouth to comment that my main collection is 31.


Can’t answer to small variations in the copper content of brass primer cups, but of course, there is still some use of copper cups, rather than brass. I can’t speak for lately, but when I was shooting a lot with .222 and .223 precision rifles, I used the Remington 7-1/2 primer and that had a copper cup, not any form of brass. I agree though, that sometimes it is hard, for purposes of deciding if the cartridge is a variation to something you have already, to decide if the primer cup is brass or copper, and I have run into the same thing, to a smaller degree, with bullet jackets, expecially now that brass jackets have become much more common than they used to be, at least in the auto pistol calibers that I collect.

Actually…if I remember correctly, RED BRASS is generally 85% copper, 15% zinc, hence the term “RED”…there is more copper as opposed to zinc, and the metal appears more reddish orange than typical “YELLOW” cartridge brass.

Gun Metal (copper, tin, and zinc) is sometimes known as “red brass” so I’m not sure there is a standard alloy that can be described that way.

Gourd, I think that the alloy used to make primer cups is directly related to what the primer is used for. Since most are nickel plated it would be difficult to tell what color the brass is without removing the plating.

In other words - I can’t answer your question either. :) :)

And being a “31” is no reason to feel ashamed. Someone has to do it. I’ll bet even Chris P. has a few hidden in his .455 collection.


There are really two main types of brass used in cartridge construction:

90/10 brass, also known as gilding metal. Commonly called copper - i.e. "Copper Jacketed"
70/30 brass, used for cartridge cases.

Gilding Metal is generally 95% copper, 5% zinc, and is generally regarded as a type of brass. Western Cartridge Company’s “Lubaloy” bullets also contained 2% tin, making this a type of Bronze alloy. Bronze is an alloy of copper and tin, in varying amounts. In case anyone is wondering, besides my primary career as a patent draftsman, my secondary career has to do with the processing of various scrap metals…Randy

Interesting subject. I had no clue about these mixes and their subtle differences. I have totally noticed different color brass (or what I thought was brass). Someone told me that one of my early era torpedo gyroscopes was made from “Red Brass”, and it is clearly different from the others in color.

PS: I did not know you were a Patent Draftsman, Randy or processed scrap metal. VERY COOL. I want to melt something now :-)