I was loading some .38 spcl 158 gr, and wanted to try some different powders, I had a small amount of H-4227 left over and found a load for the .38 that looked good and fast in Lyman's book. However I was able to check it out using P-Max Internal Ballistics program and instead of 950 fps,like Lyman says, P-Max thought it would shoot about 750 fps with only ~60% burned in the barrel!
Looks like I should have used it in the .44 with 200 gr boolets. I used it all up so won't make the same mistake again.