JB,

I disassembled some ammo a friend picked up at a garage sale for $5.00. It was pre WW 2 production 30/06 ammo with armor piercing bullets on them... he wanted the bullets to load up in a 300 Win Mag....

so I disassembled them and he let me keep the cases and the powder in them...deprimed the old primers and put new production in them...

the powder was IMR 4895 ( DuPont)... the cases were dated from 1936 to 1940.

I did an experiment testing the pre WW 2 powder against new production 4895. Test cartridge was a 22.250 with 55 grain bullets.

Velocity was pretty much the same over the chronograph....

but surprisingly accuracy champ was the pre WW 2 production 4895..