I have the above mentioned rifle, and I am getting ready to do my build. I have a few questions if someone could help me out. I am going to put a set of quad rails on it, specifically DD OMEGA 7 rails. I am also going to do an aimpoint micro T1 with a Larue LT 660. I have a few questions:

1. When I take the carrying handle off is there a picatinny rail already under the handle? The Omega rails obviously dont extend back over the receiver yet I see pictures of guns with the rail system there so the scope mount can be placed there. If the rail isnt there under the carrying handle where do I get just the flat picatinny rail to mount on the gun and whats it called?

2. I am going to put a set of folding BUIS on the gun as well, the back sight will mount on the flat rail mentioned above. I want to take off the stock fixed front sight, is this difficult to remove? I will need a new gas block in place of the fixed front sight. Are the clamp on blocks adequate and if so what size would I need for the colt LE  6920?

I apologize if these questions are basic, I just want to make sure I order the correct parts and know the correct way to mount everything!
Thanks again.

Jeff

1. Yes
2. Can be, you need a punch. Usually clamp is ok. .750 should be the size.

I just built a new rifle starting with a Colt 6920 as well.  I went with the Daniel Defense Omega X rail, but the standard Omega is a great rail as well.  I just wanted to point out that if you want to go with BUIS, you can just go with the rear fold-down sight and leave the front sight alone.  They make the rear BUIS such that they at the right height to work with the existing front sight block.  Obviously if you do not like the look of the existing front sight assembly, then you can go ahead with your plan to replace it with a gas block.  Good luck with your rifle, and the 6920 is a great platform to build on!