I want to do my own build and have decided on a DD lower and a LMT upper (16" Upper Receiver Assembly with flash suppressor Standard Flattop Upper Receiver w/ 1/7 Twist, Chrome-lined Barrel) …i would imagine that these two would fit together but i cant find any info on compatibility between manufactures…
Exactly what I run. DD lower, lmt upper. No problems whatsoever. For the most part, as long as everything is in spec, any ar upper should fit on any ar lower.