Thread: A Wander Through my Data for the .308.

Greetings,
As my handloading for the .308 approaches 50 years I thought it might be interesting to have a look at some of the data. First loads used AR2201 left over from my .303 loads and 180 grain Norma projectiles. IMR4064 entered the scene in 1979 and a change to 150 grain projectiles. I had made the transition from a reloader to a handloader. Over the years I collected stacks of data and wondered how some of the early data stacked up. Three lots of manufacturers data for IMR4064 was rounded up. These dated from 1976 (Dupont), 2003 (IMR) and current on line data (.Hodgdon). All velocities are adjusted for a 24 inch barrel. The velocities for my standard load of 46 grains of IMR4064 with the 150 grain Norma projectile were Dupont 2,825 fps, IMR 2,890 fps and Hodgdon 2,817 fps. Corrected velocity for my standard load in my rifle was 2,850 fps from my chronographing in 1991. More recently, 2020, corrected data for the same load and same lot of powder was 2,870 fps. Not much change in 30 years.
Regards Grandpamac.

Consistency is reassuring.

Originally Posted by whanahuia

Consistency is reassuring.

Especially as the powder was packed in 1978. I finished an earlier tin in 1986 and loaded some test loads of the 1978 powder which showed it shot higher than the older stuff. I dropped the load from 47 to 46 grains which shot to the same place. Later with a chronograph I found that the 1978 powder gave around 40 fps more velocity than the old stuff.
GPM.