The LMT Defense MARS-H CQB is a semi-automatic 7.62x51 NATO (.308 Win) rifle built on LMT's Monolithic Rail Platform. It pairs a 16-inch chrome-lined chromoly barrel with a 1:10 RH twist and a monolithic upper milled from a single aluminum forging. The rifle ships with ambidextrous controls and a two-stage trigger for repeatable operation. 
 

Key Specifications 

• Brand: LMT Defense 
• Model: MARS-H CQB 
• Caliber: 7.62x51 NATO / .308 Win 
• Action: Semi Auto 
• Capacity: 20 Rounds 
• Barrel Length: 16 in 
• Finish: Black 
• Twist Rate: 1:10 RH 
   

Detailed Features 

• Monolithic Rail Platform (MRP) milled from a single aerospace aluminum forging for upper and handguard alignment 
• Chrome-lined chromoly barrel with a 1:10 RH twist chambered for 7.62x51 NATO 
• Two-stage trigger for a controlled, precise break 
• Ambidextrous lower controls: bolt catch/release, magazine catch, and safety selector 
• Low profile gas block with a straight gas tube 
• Includes a 20-round magazine, owner's manual, and 3 rail panels

Shooters who run an LMT MARS-H CQB in 7.62x51 tend to focus on the Monolithic Rail Platform first, since a one-piece upper and handguard removes the usual point of flex where a barrel nut and handguard meet on other ARs. That rigidity is the main reason buyers move up from lighter .308 pattern rifles, and most owners report the rifle tracks well through repeated strings of fire.

Ergonomics get consistent credit too. The ambidextrous controls matter more on a 7.62 platform than a 5.56 gun, since the extra weight and recoil make fast reloads and safety manipulation from either shoulder more useful. The two-stage trigger is usually singled out as smoother than what ships on comparable factory .308 rifles, though a few owners still swap it for an aftermarket unit to match personal preference.

Value opinions split along expected lines: buyers already sold on LMT's reputation see the MARS-H as a straightforward step up in a caliber they already trust, while shoppers comparing purely on price note that monolithic-rail .308 rifles cost more than standard two-piece uppers. Parts support through LMT is generally viewed as a plus for long-term ownership.