[LoadedDrum]

Get rid of the lightening cuts in the rails. It will make the uppers easier to manufacturer and give better accessory compatibility.

Lighter trigger.

medium contour barrel 1/7 twist.

 

[LoadedDrum]

I run an LT104 on one of my XCRs. There is enough contact between the existing rail and the larue "cross bar" to prevent fore and aft movement. Full profile rails would give me much added piece of mind however. I don't know where lightening cuts originated but they are showing up in far too many places for my taste. Even the 556 SWAT has them on the forend. Daniel Defense has long proven you don't need them to make a light rail system.