The Firing Line Forums - View Single Post - Any ideas about what caused the spot on shell

Pathfinder45 · May 19, 2019, 08:47 PM

I think it's chemically induced corrosion from a contaminant. Could be something as simple as sweat from your hands or a multitude of other possibilities. Chlorides are bad for copper and its alloys: https://en.wikipedia.org/wiki/Bronze_disease
I have some ammo I loaded 20 years ago that is starting to show some tarnished spots on the outside, but upon dismantling the worst round, I found all was clean and shiny on the inside. Some ammo can go horribly bad on the inside in an alarmingly short time, due to destabilized powder.

May 19, 2019, 08:47 PM	#2
Pathfinder45 Senior Member Join Date: January 7, 2008 Posts: 3,224	I think it's chemically induced corrosion from a contaminant. Could be something as simple as sweat from your hands or a multitude of other possibilities. Chlorides are bad for copper and its alloys: https://en.wikipedia.org/wiki/Bronze_disease I have some ammo I loaded 20 years ago that is starting to show some tarnished spots on the outside, but upon dismantling the worst round, I found all was clean and shiny on the inside. Some ammo can go horribly bad on the inside in an alarmingly short time, due to destabilized powder.