I replaced the rear peep sight on my 110 with a Williams Ghost ring sight that has a green fiber optic that gives you 2 dots on each side. It's designed for shotguns but it's fits the rear base with no problems. I have not tried the sight yet, as I've been working with my Scout scope. I do find that the front of the rail covers up the bottom half of the front sight and I may make modifications to the front of the rail by having a tapered channel milled in front of the rail screw at the end of the receiver to the front of the rail.

Also, what ammo are you shooting? I find that my Scout likes 175 grain bullets (Sig 175 gr Match). I've tried some 150 gr and they were inconsistent (depending on the brand, I.e. Winchester white box, Armscor, Aquilia).