Thread: Red colour inside 44-40 case??

Originally Posted by Marty Henry

May be copper due to a change in the metal caused by powder residue and moisture during storage, however it's not going to affect it's performance.

Dezincification of the brass. The zinc is mixed in to improve the brass's ductility and tensile strength - and the zinc is a lot more reactive than the rest of the bronze and other elements so corrodes out first leading to the characteristic pink colour. I am told it can be caused by breakdown of the propellant especially if there is a bit of contamination in the case - quite possible with handloads. Apparently the propellant breaks down into acid and a nonreactive component and the acid is what causes the dezincification process. Now if you've changed the components making up the brass case you've changed the ductility and strength of the case. Up to you if you want to use them, but you only get one face.