My thanks to ALL the guys who were thoughtful enough to share their knowledge and personal experience about ammo for my new S&W M&P 340 CT .357 Magnum revolver. I paid attention! I now have five different kinds to try out to decide which will suit me best for practice or carry or both, and they are (in random order and no preference, yet):

. Hornady .38 Special Critical Defense 110 Gr. FTX JHP 1010 fps/249 ft-lbs muzzle.

. Federal Premium .38 Special Personal Defense 110 Gr. Hydra-Shok JHP 980 fps/235 ft-lbs muzzle.

. Federal Premium .38 Special Personal Defense 125 Gr. Nyclad HP 850 fps/191 ft-lbs muzzle.

. Hornady .38 Special +P Critical Defense 110 Gr. FTX JHP 1090 fps/290 ft-lbs muzzle.

. Speer .38 Special +P Personal Protection 135 Gr. Gold Dot - Short Barrel HP 860 fps/222 ft-lbs muzzle.

I'm indebted to you all.