I have them on my .38 Special,. 357 Magnum, & .41 Magnum revolvers. Their grips help cushion the recoil of heavier loadings in those calibers as well as facilitating a good "grip". Especially helpful to those of us with arthritis.
Now for the bad. If you utilize them on blue steel revolvers or pistols, periodically remove and check beneath them. Water/condensation, sweat, and dirt can collect between the rubber and steel to form rust. Fellow officers who used Pachmayr's on their revolvers and semi-automatic pistols experienced this. Otherwise, they are GTG.
HTH.
JPJ