I have a carry a M 638 for summer carry. This is one of my two favorite sidearms. The other is mt Colt Commander pre Series70 LWT in 45acp.
The S&W really likes heavy bullets. It especially likes 147 +p Winchester hollow points into one ragged hole at 25 feet.
If I could suggest a bullet, I would say try the heavy weights, 158 lead +P hp are excellent defensive bullets. Yea they do recoil a bit more, but its worth it.
Good luck,
CW