Speer #7 only had two powders listed for the 158 gr LSWC, 2400 and Unique. The 12.0 gr of 2400 load was shot out of a 6" K-38 at 1100 fps. When you got to the half jackets, the powders expanded to include Al-8 and AL-5. I used 10.0 gr of AL-8 with the 146 gr HP in my Chief's Special. It was just a little bit faster than 11.0 gr of 2400. A set of Pachmayr's would have helped tame the recoil a little.