I loaded behind a 158 gr LSWC. I thought I was shooting black powder!
They were accurate, and out of my 4" 686, I felt like Jerry Miculek on the steel targets! Yeah, I ended up with a black cylinder, black left hand from the speed reloads, but a huge grin at the end of the day! If I had a M28, It'd probably feel like I was shooting a .22!