I have recently been looking into reloading for the 7.62x39 and after researching for quite awhile I couldn't find any data on the temperature sensitivity of CFE-BLK. It is advertised as a suitable powder for the cartridge so I did some of my own testing and wanted to share the results in case anyone else is wanting to use this power for any cartridge subjected to temperature differences. I loaded 10 rounds total with 123 Lapua FMJ in Lapua cases, and had 5 at room temperature and 5 in the deep freeze at -18*C.
At -18*C the FPS results are:
Max -2272
Min -2248
Avg -2258
S.D -12.2
21*C Room Temperature:
Max -2372
Min -2359
Avg -2364
S.D -6.7
Difference Between The Two
Max - 100
Min - 110
Avg - 106
S.D - 5.5
So in conclusion I am actually impressed with the stability of this ball style powder. For a 39*C temperature difference and an average of 106 fps difference is acceptable in my books. It is not as stable as Hodgons Extreme Extruded line, but until I can get my hands on some H4198 for testing this will be a good start. As always this is my collection of data and use at your own risk, happy shooting.
At -18*C the FPS results are:
Max -2272
Min -2248
Avg -2258
S.D -12.2
21*C Room Temperature:
Max -2372
Min -2359
Avg -2364
S.D -6.7
Difference Between The Two
Max - 100
Min - 110
Avg - 106
S.D - 5.5
So in conclusion I am actually impressed with the stability of this ball style powder. For a 39*C temperature difference and an average of 106 fps difference is acceptable in my books. It is not as stable as Hodgons Extreme Extruded line, but until I can get my hands on some H4198 for testing this will be a good start. As always this is my collection of data and use at your own risk, happy shooting.