Taking the 639 completely down several times, I'm thoroughly convinced the M639 could last for 100 or more years. A true tank, I recently replaced the recoil spring and magazine springs. Neither needed replacement, but the springs are cheap. Literally thousands of all type 9mm has been shot through my 639 with one (1!) stove pipe on a reload. I was so shocked I threw the crunched round in the pistol box 8 or 9 years ago where it remains. My 639 has popped off countless rounds of +P as well. With the newer 9 round 39 S&W mags and the ability to carry another safely in the tube, the 639 is still a pistol holding its own in the tupperware era. Just wish it held 16 or so.