I finally found a machinist with tooling to make some of these collared inserts..
https://goo.gl/photos/x3KCfhdaGStZqve28
I have been using them for a while now. Does OMC still sell them? Still have several set. I do like them better than the flush fitting inserts.
OMC told me they were discontinued.
Well that's a bummer.
And the reason for the collar?
It kind of acts like a second pin. I like how the limb fits on the riser with them. I use to put two pins in my bows now I just use one.
No intent to hijack the thread, would a regular self centering dowel jig work?