Terry Wieland has done a nice story on this very subject , Self-Defense Loads in a Time of Drought, Aug. 2013 issue Handloader Magazine. Tested 38 special , inverted hollow base wadcutter, in a J-frame S&W , 2 inch barrel, velocities were chronographed as fired from the 2 in. barrel, bullets were fired into a box of packed newsprint ( not stated if paper was wet or dry ) assuming dry newsprint, at 5 yards.
Results, all loads using Bullseye powder and 148 hbwc ( no brand given )
3.2 grs. 724 fps -no expansion
3.3 grs. 740 fps - slight expansion
3.4 grs 767 fps - expanded to 5/8 inch dia.
3.5 fps 801 fps -good mushroom, .715 inch dia. retained weight 144 grains....THE WINNER
No mention was made of accuracy but he shot them all into a bullet box at 5 yards. no mention of keyholing either.
I was glad to see this article, I wanted to try this and after reading all my books and etc. , I came to the assumption that 2.8 grs. of Bullseye would give me 810 fps, and it might in a 6 inch barrel, but this information proves 3.5 grains is what is needed. At least I had the 800 fps velocity right.
I got Bullseye now the HBWC quest is on. I been looking on local dealer's shelves, but no luck so far.
Gary