Some nice revolvers folks. Mine does shoot great, especially with the original full coberage rubber grips. My one and ONLY complaint is for a pure fighting weapon they should have at least installed a tritium night sight on at least the front for nighttime use.
Mine does not have the stamp, nor has it tied up in the 500 or so rounds I put through it. My no dash 586 never had the M Mod either and has always functioned well in over 20k-22k rounds. I shoot the heck out of it and it's my only .357 I've ever shot Buffalo Bores 180 gr. loads through. If I ever again need that much power I'll choose my 6" model 57 with 8.5 grains of Unique with a hard cast LSWC on top. Them 180 grainers have a definate slap to the hand factor, but will take a good sized deer down quickly. I would never shoot that round through ANY of my K models.