FE7317 Flashlight Check

[Mechanician]

^^^ It almost looks like a coating. Need a couple more photos.

I'm afraid there's nothing remarkable about it. It's just the optics of the angle in the photo.
It is a little interesting how much the retaining bumps on the cartridge make impressions, each time it's installed.
It is a tight fit, the distortion of the "seat" is pretty obvious compared to the first photo after tear down.

 

[ZeeOSix]

^^^ Yeah, those "nubs" on the inside circumference of the end cap hole are really digging into the leaf spring.