The rails on the uper reciver and the handguards are they the same with as the scope baes on my rifle? I dont have a ar15a4 or a handguard with mounts on it so i want to know before i get it.

Well, you don't say what rifle you have or what scope base it has on it, but I'm guessing you have a hunting rifle with a Weaver base.  If so, then the rails on the AR are simillar and usually compatible but they are not the same.  

Also, while the rings you use on a hunting rifle can attach without any problems they will probably be too short to use on the AR unless you also use a riser rail to make it taller.  The center of the scope will need to be about the same height as the iron sights you normally see on the AR.

The KAC RAS's handgaurd rail is the same mil-spec. width and height as the rail on the upper receiver.

Quoted: Well, you don't say what rifle you have or what scope base it has on it, but I'm guessing you have a hunting rifle with a Weaver base.  If so, then the rails on the AR are simillar and usually compatible but they are not the same.   Also, while the rings you use on a hunting rifle can attach without any problems they will probably be too short to use on the AR unless you also use a riser rail to make it taller.  The center of the scope will need to be about the same height as the iron sights you normally see on the AR.

this would be my guess too. weaver and picatinny are similar and would work but not the same

Yeah weaver. remington 700 kind of bases.