I never could find sights with the right thread size for my 5100's; I finally ordered ones from Brownells that have the ivory post, turned down the posts a little and epoxyed them in. The middle beads are indeed press fit; gunsmither's instructions for getting them out are good. If you use those make sure the new bead base isn't too long; I put one in that I never could get flush and had to re-do it, and there ain't no taking them out without destroying them!

Fin

The difference between genius and stupidity is that genius has its limits. - Albert Einstein