I was told many years ago by a gun shop owner that he knew of a few
early md 60s that were damaged by Super Vel factory loads. He
insisted that the stainless used in the 60 was softer and less tough
and durable than the carbon steel of the 36. He claimed that S&W
stainless revolvers would shoot loose faster than carbon steel models.
He claimed that he had proven the difference in hardness by using
a file on the inside edge of the grip frames several times. I was also
told by a retired cop friend that back in the days when they all used
revolvers that the S&W 66 would loosen up much faster than the 19
with the same amount of firing. Don't know. I have a 60-7 and two
37-2s. I plan to stick to standard pressure in the 37s and no more
than +P in the 60. Can't believe that higher pressure loads would
compensate for poor shot placement at close range.