CFE-223 may not be age-stable powder!
Today, I was updating the GRTools powder model for CFE-223
load data:
175gr RDF
45.2gr CFE-223 @ 2.800"
Federal LR Match, Lapua 308 case
Howa 1500 22" 1:10
Average MV 2709 fps at 68 (Labradar)
Last year in Summer 2021, I had an almost identical load:
175gr RDF
46.3gr CFE-223, @ 2.850"
LR (S&B or CCI not sure), same Lapua 308 cases
Howa 1500 22" 1:10
Average MV 2648 fps at 91F (Labradar)
First, you notice that the aged powder produced more MV with 1.1gr less powder and at lower ambient temperature.
More MV means more Pressure behind the bullet.
Thus, I calibrated the CFE-223 to the new observed values for the load data I loaded for last Sunday. The powder model was named CFE-223-2022
Then, I added a relative bullet jump of 0.050" for last year's powder model to accommodate the different COAL between the two loads, 2.850" (old) vs 2.800" (new)
Then, I calibrated the powder last year observed MV of 2648 fps at 91F and named the powder model CFE-223-2021.
GRTtools revealed:
Summer 2021 CFE-223 Ba is 0.5335
Spring 2022 CFF-223 Ba is 0.5430765
Today, I was updating the GRTools powder model for CFE-223
load data:
175gr RDF
45.2gr CFE-223 @ 2.800"
Federal LR Match, Lapua 308 case
Howa 1500 22" 1:10
Average MV 2709 fps at 68 (Labradar)
Last year in Summer 2021, I had an almost identical load:
175gr RDF
46.3gr CFE-223, @ 2.850"
LR (S&B or CCI not sure), same Lapua 308 cases
Howa 1500 22" 1:10
Average MV 2648 fps at 91F (Labradar)
First, you notice that the aged powder produced more MV with 1.1gr less powder and at lower ambient temperature.
More MV means more Pressure behind the bullet.
Thus, I calibrated the CFE-223 to the new observed values for the load data I loaded for last Sunday. The powder model was named CFE-223-2022
Then, I added a relative bullet jump of 0.050" for last year's powder model to accommodate the different COAL between the two loads, 2.850" (old) vs 2.800" (new)
Then, I calibrated the powder last year observed MV of 2648 fps at 91F and named the powder model CFE-223-2021.
GRTtools revealed:
Summer 2021 CFE-223 Ba is 0.5335
Spring 2022 CFF-223 Ba is 0.5430765