What kind of brass for Smith cartridges?

[Maillemaker]

Does anyone know what kind of brass is appropriate for the brass Smith tubes?

As in, how to specify it for an engineering drawing.

Free-cutting alloy C360 ?

Thanks,
Steve

[John Bly]

Yes, I would note to use C360 brass. It is a free machining brass readily available in rods

[Kevin Tinny]

Hello, Steve and John:

I have been down the brass case alloy road with three cartridge case makers:
Rocky Mountain Cartridge, Roberson Brass and STARLINE.

For DRAWN cases and those destined for over 50,000 psi pressures, STARLINE and Roberson use alloy C260 yellow cartridge brass with annealing after drawing or turning steps. RMC, which has TURNED many ctg cases for BLACK POWDER, has always used C360 free machining in "HALF-HARD" temper.

Regardless of the brass alloy, thin wall cases will need annealing. I never found that the much thicker walled Smith ones did.

Your shop might ask about brass alloy bar stock TEMPER, so half-hard would be it.

RMC said C260 is more for drawn cases and Roberson told me they also use C260 in BAR stock for a slight increase in strength with smokeless, center-fire "wildcat" cases.

We've reviewed the Smith case topic a lot here, and I found the black PLASTIC cases from Back Creek, with a steel pop rivet body as a flash hole liner, do just as well as my brass and stainless ones. Plastic's are cheaper and lighter, too. Just saying... Smiles.

Kevin Tinny