A few days ago I chronographed two 45 Colt loads using Black MZ under 256g RNFPs from Montana Bullet Works.
First load was a dipped 1.9cc charge, settled in the case by tapping on the bench top. The results were:
USFA 7.5" SAA = 842 fps
USFA 5.5" SAA = 749 fps
USFA 3" Sheriff = 659
Next I tried a dipped 2.2cc charge, again settled by tapping on the bench. This produced:
USFA 7.5" = 916 fps
USFA 5.5" = 831 fps
USFA Sheriff = 711 fps
The 1.9cc charge was pleasant to shoot but short of the performance I was looking for. The 2.2cc charge was exhilarating but hard on the knuckle of the middle finger on my shooting hand. (smile)
25+ years ago I shot 35g of FFFg behind 255g soft cast RNFPs and got results similar to the 2.2cc load ion the 7.5" barrel, but not for the 5.5" gun. It's performance should have been more like 875 fps or there abouts.
I also noted a wide extreme spread for all the loads tested. That leads me to believe I need either a lot more practice dipping powder charges, or a better way to meter this Black MZ. It is very course.
Any suggestions or recommendations for more uniform charges (short of weighing each one) would be appreciated.
Dave