Which Smith Mount? Weaver or Picatinny?

I though is a standarised Weaver.

My Smith mount is Picatinny. Bought some Leupold low rings, works like a champ.

The slots are a little wider on the picatinny. Weaver rings will fit, but they will have a little slop unless you push them forward while tightening them. Picatinny rings will not fit a Weaver rail. I would get a Picatinny base so you can use either type of ring if you need to.

Thanks for the info

Go Picatinny. All the top rings are made for the Picatinny rail. Why limit yourself?