I was talking to a buddy this morning and he was telling me his wife likes his M&P 40, but the round was a little too much for her to shoot accurately. I have loaded some 38 special with IMR Trail Boss. What I found with Trail Boss was less recoil and report, accurate shooting with a lower velocity. I have only loaded lead SWC projectiles with Trail Boss. I shared my experiences loading this powder with my friend. We both wondered if it would be a good powder to use in self defense rounds for his wife. I looked and didn't find any loads for anything but cowboy rounds for Trail Boss and was wondering if anyone had experimented with it in a semi-auto weapon. My skepticism comes in wondering if you would get enough blowback to properly operate a semi-auto.