Thread: Blending powders

Originally Posted by 6x47

Might be a dangerous assumption from what serious Férs have found in the US. Apparently some batches of H4350 (2209) are significantly different .

Greetings All,
I tested this in my 6.5x55 a couple of years back and found that the same load of 2018 AR2209 gave around 80 fps more velocity than either of my earlier two batches circa 1990 and 2000. This was done with all other components the same, loaded and shot on the same day. The chronograph readings from loads from years back showed that the older powder had not changed in speed over the years. It appears that this change happened in the 2000 to 2002 period. 80 fps is roughly the same as adding another 1.5 grains of powder. I could also find sets of load data that matched the two speeds.
For this and a number of other reasons I think mixing two lots of a powder is a thoroughly stupid idea. You are adulterating your new lot by mixing it with older powder and it is easy to do a simple test. Load two cartridges of the old lot and two of the new and chronograph them. If they are close to the same then all good. If not then you can easily calculate and work up to your new charge with a few rounds. New batches of projectiles need to be checked as well. Later Hornady projectiles have their ogive in a different place and seating depth needs to be adjusted.
Regards Grandpamac.