teehee
Are you seriously that lazy to not notice the OP?
Yes, I view the latest page first. I knew Gravity would make the mistake he did with the model. You gave the gun a STANAG magazine but said it did more damage than the SA80. The XCR can be chambered in 7.62x39mm and 5.56, the magazine you gave it would make it 5.56, firing the same caliber as the SA80 and doing the same damage as it.
http://www.youtube.com/watch?v=C7JHbnLy8ekBasically just add more curve to the magazine, I also think you should change the sight on the gun to a holosight.
You should also add a gas block to it, the random cylinder sticking out of the front of the gun looks handicapped without it.