Hey Guys,
Newbie here. I recently purchased an Bushmaster A3 M4 and a weaver grand slam 4.5-16 scope.

I have mounted the scope to that handle since there isn't any brackets high enough clearance.

But it even with the windage adjustments, I can't seem to sight my rifle correctly. It seems the front of the scope is tilted too far up. I added some piece of paper to the lower bracket that sits closer to the butt of the gun. This seem to raise the scope, but not enough.

Any suggestions??? Different brackets??? Any hellp would be much apprieciated

A pic of the gun below

http://i82.photobucket.com/albums/j267/oregonasian/A3M4.jpg

Do I have to use weaver mounts??