LMT MARS-H 16" .308 Win. Marksman Rifle Build

In this Brownells Tech Tip, Caleb walks through a complete LMT MARS-H 16 inch .308 build, setting it up as a designated marksman rifle optimized for precision and durability. From configuring the correct buffer system to installing the barrel, trigger, stock, optic, and suppressor, this large frame AR build covers everything you need to know to assemble a reliable .308 battle rifle or DMR platform. This build features the LMT MARS-H monolithic upper and ambidextrous lower, an LMT two-stage match trigger, A5 length buffer system, Magpul PRS Gen 2 stock, Nightforce NX8 optic in a Spuhr mount, SureFire SOCOM 762 suppressor, MDT Arca bipod setup, and more. Caleb also takes the rifle to the 500 yard range to confirm performance in windy conditions, working from 100 to 500 yards and ringing a 6 inch plate at distance. If you are building a .308 AR, LMT MARS-H, or setting up a precision AR-10 style rifle for long range shooting, this video walks you through the full process step by step. Chapters: 00:00 LMT MARS-H 16 inch .308 Build Overview 01:04 Lower Receiver Setup and Parts Overview 02:11 LMT MARS-H Buffer System Explained 05:24 Installing the A5 Receiver Extension and Castle Nut Staking 07:59 Installing the LMT Two-Stage Match Trigger 11:59 Magpul K2 XL Grip Installation 14:24 Magpul PRS Gen 3 Stock Installation 17:00 Upper Receiver Setup and Barrel Installation 20:15 Installing the SureFire 3-Prong Flash Hider 21:36 LMT .308 Iron Sights Installation 25:19 Arca Rail, MDT Bipod, and M-LOK Accessories 28:40 Charging Handle and BCG Installation 31:52 Mounting the Nightforce NX8 in Spuhr Mount 34:40 Function Check 35:32 Range Test at 100 to 500 Yards 41:15 6 Inch Plate at 500 Yards 42:24 Final Thoughts on the LMT MARS-H Whether you are tuning a large frame AR buffer system, installing a quick change LMT barrel, or setting up a suppressed .308 DMR, this build delivers practical, bench level guidance you can apply to your own rifle.