They just don't hold up to more than a very few thouand rds of full charge mag ammo. they send a couple of M19's to HP White labs, and neither one made it to 2000 rds without significant damage to the forcing cone or the frame in that area. Did you know that the hammers and triggers of M66' are not stainless steel, other than a very few early models? those parts are hardchomed, because the stainless ones were too soft, and would not stay cocked after a bit of wear. also, the early M66's, if fired 6 rds swiftly, would lock up and not let you open the cylinder. They had to swap out the little "gas ring" at the front of the cylinder, for a hard chromed version. the SS one would "swell" with the heat of such firing.