I knotted one end of a string, and tugged it against the .625 tube end to start, followed it around the outside of the pipe in the flair-bend radius, inch wormed my finger all the way to the very end of the stinger tube and came up with 12 inches right on the button.

Mine is a half-inch shorter overall on the outside curve, .060" fatter across the halves, so it must be the stumpy HP.

I'll try and snap a good pic with a tape measure with it, maybe you can pick something up that I have missed.

If I knew this morning I was going to be holding a camera I would have backed off the coffee.

This is the squarest image I can come up with and the best focus my webcam can muster.