This is more of a heads up than anything, I ordered 3 of these (order 659227) and one of them is out of spec on height/width of the actual shaft of the handle.  It would roughly go into an upper, but would take mortaring the rifle to try to get it back out.  The other two work perfectly fine though.

I'm not worried about a replacement as trying to get it to work, I hit some of the rough spots with some 2000 grit and alumablack to try to make it work smoother with no luck.  It absolutely refuses to work in 3 different milspec and one billet upper.

Thought I'd at least give a heads up.