Weaver style bases, whats with the different slot size?????????

[canadaman30]

Was out today for rings and bases, the base I usually buy (Leupold Rifleman one piece) were out of stock, so I was sold a Weaver extended multislot (picatinny style) base. Once home I noticed the cross slots in the Weaver base are a little wider than the Leupold base. The rings I'm using are Leupold PRW, when I loosen the rings off and put them in a base slot there is a lot of play, as the cross slot lug on the ring is alot smaller than the base slot. Yes there is a little play with the Leupold base but, alot less. Why are the slot sizes on the bases different, and will it make any difference once the rings are tightened down to the base. One other question, does anyone use adhesive on any thing else besides the base screws when scope mounting. thanks for any help.

[JustaShooter]

There is no standard for slot size and spacing for Weaver bases, and are often custom to a particular application. Picatinny rails on the other hand have a specified slot size and spacing.  See http://www.brownells.com/.aspx/lid=10724/GunTechdetail/Picatinny-Rails-Weaver-Rails-What-s-The-Difference-

The play shouldn't matter once things are tightened down, just make sure the cross slot lug is tight against the front of the slot.

As to adhesive, I don't use anything on my scope ring screws or base screws for that matter, though I know some that use blue loctite on base screws, never heard of anyone using any on the ring screws.

[Hairy Chest]

Exactly as said above.  Picatinny is is good.  You can switch to a red dot because you have more mounting options.  If it is a 10/22, be careful torquing the mount screws because the receiver is aluminum.  If the mount needs to be really secure and not easily removable you can use Loctite Red or Epoxy.  That thing on the left has red and after a few hundred rounds it hasn't moved.