The Luth-AR 5.56 Lightweight Barrel is not chrome lined. Its specifications include:
4140 Chrome Moly
Threaded Barrel — Thread Pitch 1/2 x 28
Gas Block Diameter .750
Gas Tube Length — Carbine
1-9 RH Barrel Twist
6 Lands and Groves
M4 Feed Ramp
Button Broached
Weight: 1 lb 12 oz