How old can shotshells be before becoming dangerous to shoot(pressure increase from old smokless powder)?

I have some Remington 3" 20G (yellow plastic) from the 1970/80's that are turning dark gray to black (yellow plastic staining) near where the powder lies in the loaded shell.

John

Last edited by smilinjohn; 10/07/07 01:33 AM.

We're only responsible for the effort, not the outcome.