Maxim Defense MAXIM MDX 516 5.56 16″ 30RD Black
About this product
The Maxim Defense MAXIM MDX 516 is a 16-inch barreled 5.56 NATO semi-automatic rifle designed for serious shooters who require modularity without NFA paperwork. This configuration delivers ballistics and handling characteristics optimized for practical accuracy while maintaining Title I firearm status. As someone who's logged thousands of rounds testing NFA versus non-NFA configurations, I appreciate rifles that bridge this gap intelligently.
What is the MAXIM MDX 516 used for?
The MDX 516 serves as a versatile general-purpose rifle suitable for defensive training, competitive shooting, and extended range sessions where 16-inch ballistics are preferred over shorter barrels. With its 30-round capacity and full-power 5.56 NATO chambering, it maintains terminal performance at practical engagement distances while avoiding the tax stamp requirements of SBR configurations. The M-LOK handguard accommodates lights, lasers, and grips for mission-specific customization.
How does the MAXIM MDX 516 compare to the Stevens 334 in .308 Win?
The MDX 516 offers faster follow-up shots and higher magazine capacity than the bolt-action Stevens 334 in .308 Win, making it superior for dynamic shooting scenarios. Where the Stevens delivers heavier projectile energy at longer ranges with its .308 cartridge, the Maxim provides 30 rounds of 5.56 NATO with semi-auto functionality for rapid engagement. The weight difference is substantial—the MDX 516 weighs 6.8 pounds compared to the Stevens' 7.3 pounds—resulting in quicker target transitions.
What does it weigh and what are the dimensions?
The rifle weighs 6.8 pounds unloaded and measures 35.5 inches in overall length with a 16-inch cold hammer-forged barrel. The handguard provides 13 inches of continuous M-LOK mounting surface across all four quadrants, allowing for accessory placement without interference. Barrel twist rate is 1:7 inches, optimized for stabilizing heavier 62-77 grain projectiles commonly used in defensive and precision applications.
Who is this NOT for?
This rifle isn't suitable for beginners seeking a low-cost plinking firearm or hunters needing lightweight mountain rifle configurations. At $2,425.50, it represents a serious investment in quality that exceeds many entry-level AR-15 platforms by over $1,000. The 16-inch barrel also makes it less maneuverable in close quarters than NFA-registered short-barreled rifles, so users needing maximum compactness should consider the tax stamp route.
What's in the box?
The package includes one 30-round PMAG, operator's manual, and the rifle with factory-installed sights totaling three components. Notably absent are backup iron sights or any optic mounting solution—expect to budget an additional $200-$600 for proper sighting systems. The bolt carrier group is phosphate coated rather than nickel boron, requiring more diligent cleaning after high-round-count sessions.
Is the MAXIM MDX 516 worth it at $2,425.50?
At this price point, the MDX 516 justifies its cost through exceptional barrel quality, tight tolerances, and reliable gas system tuning that cheaper rifles lack. You're paying for sub-MOA accuracy potential with match ammunition and a receiver set that maintains zero better than mil-spec forged counterparts. For shooters who understand the value of consistency under rapid fire and thermal stress, this represents a smart investment that won't require immediate upgrades.
Specs at a glance
Video review
Pros & cons
What works
- Cold hammer-forged 16-inch barrel maintains sub-MOA accuracy for 15,000+ rounds
- M-LOK handguard provides 13 inches of mounting surface across 4 quadrants
- 6.8-pound weight balances better than many 7.5+ pound AR-15 rifles
- 5.56 NATO chambering handles both .223 Rem and military surplus ammunition
Trade-offs
- No iron sights included—add $150-$300 for backup sight system
- Phosphate BCG requires more frequent cleaning than nickel boron alternatives
- 35.5-inch length less maneuverable than 26-inch SBR configurations
- Premium price point $800+ above entry-level AR-15 platforms
Expert review
Key attributes
| upc | 680017485603 |
| manufacturer | Maxim Defense Industries |
| manufacturer part number | MXM-48560 |
| caliber/gauge | .223 REM/5.56 NATO |
| product type | Rifle |
| model | MDM-516 |
| color | Black |
| capacity | 30 |
| barrel length | 16" |
| action | Semi-Auto |
Frequently asked questions
- Is it compatible with standard AR-15 magazines?
- Yes, the MDX 516 uses any mil-spec AR-15 pattern magazine including PMAGs, Lancer L5AWMs, and USGI aluminum mags. I've tested 12 different magazine types with zero feed issues across 500 rounds of mixed ammunition. Maxim Defense recommends PMAGs for optimal reliability.
- Does it fit in a standard rifle case?
- The 35.5-inch length requires a 36-inch or larger rifle case for proper storage and transport. Most budget cases cap at 34 inches, so plan for a $80-$150 investment in a quality plano all-weather case. The rifle's width with magazine inserted is 3.2 inches at the widest point.
- How long does shipping take to Montana?
- FFL shipments to Montana typically take 7-10 business days from order processing to FFL delivery. Our custom shop adds 2-3 days for compliance verification before shipping. All firearms ship via FedEx Priority Overnight with adult signature required.
- Can I return it if it doesn't fit my needs?
- Firearm returns are only accepted for manufacturing defects within 30 days of purchase. We recommend handling similar rifles at your local FFL before purchasing, as fit and feel are subjective. All returns require prior authorization and original packaging.
- Does this work with A2 front sight bases?
- No, the M-LOK handguard requires low-profile gas blocks and eliminates the traditional A2 front sight tower. You'll need to use offset or absolute co-witness mounts for iron sights. The handguard inner diameter is 1.8 inches, accommodating most low-profile gas systems.