Cartridge Case, .44-40 Winchester, unprimed brass, correct head stamp, by Starline, each piece, no minimum order
Starline has the following recommendations for case preparation for bottle neck rifle brass: During the final polish process we treat the case with a corrosion inhibitor which keeps the brass from tarnishing and also acts as a lubricant for the first loading. This treatment is necessary for ease of priming and the sizing of new brass ( standard case lubrication will still be necessary), but it can reduce bullet tension.
Starline suggests neck sizing or running the expander ball through the mouth of the case and then chamfering the case mouth inside and out prior to loading. The expander ball works two-fold, it removes most of the corrosion inhibitor in the case neck and also makes the cast mouth round for chamfering. Cleaning with stainless media can also remove this coating, making loading a little more difficult.