I have done some checking and concluded that the conditon pictured is normal. First, that breechblock is not machined as part of the slide. The slide is a shell of heavy sheet metal, formed and shaped with some machining; the forged breechblock is held in by lugs and welding.
The welding is normally done so neatly that most gun owners don't ever know it is there. That weld is a bit sloppier than usual, but there appears to be no problem. What appears to be a crack is a line from the forging dies.
Last edited by James K; July 9, 2010 at 03:13 PM.