dust cover cracking is from the rail being a couple hundredths too high. Looks awful thin where it cracked. Suspect when the slide cracked it twisted (they only show a crack on the left side) putting pressure on the dust cover. Agree with Jake on the cause. Why ball cutters aren't used more for serrations is beyond me. A nice square corner where the slide is thinner and the slide is stressed on recoil is just goofy.
-rvb
-rvb