Where to find something like this?

[thomae]

Wondering about sliding blade or aperture rear site. does anyone make them for the top of a savage reciever?

Yes, Williams does. That's what's on the Savage FCM Scout rifle.

I thought about the Williams but which one.

Look at the page 13 of the Williams online catalog (http://www.williamsgunsight.com/guns...12_Catalog.pdf) or the page for Receiver Sights (http://www.williamsgunsight.com/gunsights/wgrs.htm) There you will see

70274

WGRS-SAVAGE

For Savage 110 with round receiver.

$38.95

You can also purchase any standard threaded adjustable aperture (Target or Hunting) and screw it into the hole in the sight. That's what I did with my Scout rifle and it was a big improvement. I have this one: http://www.midwayusa.com/product/663...s-sights-black

If you want, you can get this to convert it to a fiber-optic ghost ring rear sight.:

70919

FIRE SIGHT GHOST RING APERTURE

Fire Sight Ghost Ring Aperture. Convert any WGRS sight to the speed and accuracy of a ghost ring now with the light gathering effects of fiber optic.

$9.95

Does it require machining?

Nope. (...at least, not for a round back receiver)
You can also get a WGOS barrel mounted blade sight (see page 13 of the catalog) , but that would require some machining (drill and tap two holes) in the barrel.

I hope this information, and the references, serves to help you make a good decision. You are welcome to visit and shoot my scout rifle.