Chuck,
Common sense prevails here. I have used thousands of old primers and never experienced any misfires. Sometimes the copper gets age hardened and guns with light firing pin strikes may sometimes need another strike.
With old powders, as long as there is still a smell of ether, it's good to go. Even if it's not, it still works ok but you have to start low and chronograph as the powder gets lighter from drying out. I have a small hoard of Hi-Vel #2, Reloader #11 and Lightning and use it regularly, but not in quantity.
I have and use many powders from the pre-war era and one of my favorite pastimes is loading the old cartridges with loads of the past, with bullets cast with moulds of the past. Common sense, start low and chronograph, preferably in a modern gun in the same chambering but that's usually not possible as there are not many modern guns chambered in 40-82 or 40-60 Marlin.
I have taken old 45-70 military cartridges dated from the 1880's and taken them apart and reused the powder.......powerful stuff that was!.
This is just a sampling of the old powders and primers I have and use from time to time. I have since used up a 5000 case of Cascade (CCI) small rifle primers from the fifties and had no misfires, from loading in the 223, 218 Bee, 32-20 and others.----6
![Image](http://www.hunt101.com/data/500/medium/image1250.jpg)