What do you all think?  I have an OKO Reflex sight with nothing to do and I got the idea of mounting it to my 18" Rem 870 'Black Shotgun'.  It currently has the front bead so I would have to have the receiver drilled and mount a weaver base, which is no big deal.  What do you all think?

It will be ok.  No idea if the recoil will shake it too much (never tried this with an OKO... only with a Trijicon).  

A red-dot on a shotgun can go from pointless to so-so, depending on how you use it and what you shoot.  For slugs, it can be ok.  

For shot... sometimes ok, sometimes not. It can be deceptive, depending on how the load you shoot patterns.  You may or may not have the dot in the center of the pattern for any given load, and that centering may or may not translate toward where your slugs go at all.

NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO!

Its not needed.