No one has mentioned the problems with an expanding gas ring tying up early M-66's. When writer Massad Ayoob blew the whistle on this, he was not too popular around S&W, but the revelation got us a revision that eliminated the problem.


I think it occurred only with .357 ammo. The heat of .38 cartridges didn't stall the cylinders rotating as they should. If your gun did jam with .38 ammo, please tell us here.


Bill Jordan told me in person that he envisioned using K-frame Magnums only some 10-15% of the time with full loads. And avoid hot loads with bullets of 125 grains or lighter. If you stay within these guidelines, a M-19, 66, etc. will last well.