Fitting RIS to AGM M4 GBB

[GeryFox87]

As above I've bought a LaRue copy RIS to fit my AGM M4 GBB, but when I screw it on the top rail, which is slightly more raised than the other three does not finish in,ine with the top of the reciever, it's actually off to one side, I've tried adjusting the fitting that replaces the Delta Ring but it doesn't screw back enough to push on the reciever to make the RIS secure....

So is there anything anyone can think I can do? Besides hitting myslef over the head with said RIS? lol

I also bought a Magpul MOE Handguard and that didn't fit either... I'm beginning to think the dimensions on the AGM version may be a little different, or is it just that the treads on the reciever and RIS dont match up correctly? Regardless what position I start to screw the RIS on from.... HELP please lol