It's neither Govt or Lt Wt, in fact its heavier by design. It's the S2W profile which stands for Strength 2 Weight profile.
Here's what Daniel Defense has to say:
The Daniel Defense 16” 5.56mm S2W® barrel is designed with a strength to weight profile (Daniel Defense's Heavy Barrel), a 1:7" twist rate, and a Mid-length gas system. Cold Hammer Forging of barrels has been known for decades to produce the most accurate, longest lasting rifle barrels obtainable. The Cold Hammer Forging of barrels is accomplished through intense hydraulic pressure applied at opposing angles by carbide steel hammers. During the hammering process, a mandrel is inserted into the bore while the carbide steel hammers shape the barrel around the mandrel creating the chamber, the lands, and the grooves. In addition to the aforementioned benefits, the Cold Hammer Forging process creates a defect free bore and the most consistent chamber possible.
Stripped Barrel 2.38lbs
Barrel w/ LPG 2.46lbs
All Daniel Defense cold hammer forged barrels are made from start to finish in our state-of-the-art facility located in Black Creek, GA. In keeping with our heritage of not cutting corners, all cold hammer forged barrels feature a forged chamber and heavy phosphate exterior coating or Salt Bath Nitride Finish. These barrels will prove themselves to be more accurate and last longer than a barrel that has cut or button rifling.
Product Code: DD-07-116-04095-107