I have read here that they are not the same.  I have read that many scope rings claim to work on both.  

I just found this answer over at snipers paradise:

Q: Does anyone know the difference between Picatinny and Weaver rails? Can I use Weaver rings on a Picatinny rail?

   A: The major difference between the Picatinny and the Weaver rails are the width and distance between any cross slots that are on the base. Base nominal width is .830. I have seen some that are .832, .825 and even .840 wide. There is an acceptable specification parameter with the Picatinny design. It was actually Leupold that made the design first. The Picatinny modification was only standardizing the width of the cross slots (.100") and the distance between them (.400" center to center, roughly, if I remember right). Your weaver rings should work just fine on them. At times the Weaver base was narrower than the Picatinny standard, you'll just have to check and find out, but I think you'll be okay.

SO according to this they are the same and the picatinny is only standardized the spaces on the weaver.  So any scope ring that is weaver will work just fine on a flat top AR , correct?

Yes.

I have a Springfield M1A scout.Leupold QDW will not tighten up on the base.I guess Ill measure and see what the width is.Is 830 for picatinny and weaver?

I also have an AR15 carry handle mount that Leupold QRW rings will not tighten up on enough. They tighten up OK on the Weaver mounts on my Win M70 deer rifle, my flattop AR, and a friend's ARMS mount. I suppose I'll try to find some other rings so I can use it. I like to put a scope on my AR when testing ammo.