Here is another vote for 38 Spl WC loads to start and maybe forever. Standard 38 Spl 158 grain loads at 800 fps are good next choice.

I have a M60 and found that the pretty rosewood grips on it from factory -- same pretty ones as on many M60 LadySmiths -- made the gun hard to control with anything more that 38 Spl WCs, especially in one-handed DA shooting. I ended up with set of Pachmayer Gripper grips and find I can shoot P+ loads nicely (158 grain SWCHP at 950 fps) and shoot almost as well with 158 grain SWCHP GC at 1200 fps. With those Gripper grips I have a far higher level of confidence in hitting target than with any S&W factory standard grips I have tried on that J-frame.

Niklas