I dont know about the model 66 but a few years ago I had a model 689 .357 It was fine with .38 specials but after firing about 100 rounds of 158gr .357 blazers it started to fall apart. The cylinder release came loose, the hammer wouldnt cock, and it wouldnt fire in double action mode. I had to tighten the screws on it to get it work. I sold it and got a ruger, Ive had no problems with the ruger. btw I have a taurus PT92AFS and it has been flawless with over 2000+ rounds through it. From what Ive heard the taurus revolvers just arent at the same level as ruger or S&W. But then maybe they have improved since Ive owned one.