The Beretta ARX 100 is a semi-automatic rifle chambered in .223 Remington / 5.56mm NATO with a 16-inch barrel, polymer receiver, and 30-round capacity. 
 

Key Specifications 

• Manufacturer: Beretta 
• Model: ARX 100 
• Caliber: .223 Remington (compatible with 5.56mm NATO) 
• Barrel Length: 16 inches 
• Action Type: Semi-Automatic 
• Capacity: 30 rounds 
• Weight: 6.8 lbs (108.8 ounces) 
• Finish: Matte Black 
• Receiver Material: Polymer 
• Safety Mechanism: Manual safety 
• Sights: Adjustable flip-up front and rear 
• Barrel Twist: 1:7 RH 
   

Detailed Features 

 
The ARX 100 has a modular design that allows for reconfiguration including barrel swaps and ejection port switching for left- or right-hand ejection. The polymer receiver keeps weight down at 6.8 lbs. Adjustable flip-up sights are included. The 1:7 twist rate stabilizes heavier bullets in the .223/5.56 weight range. 
 
The manual safety is ambidextrous. The rifle accepts standard AR-15/M16 magazines. The grip is ergonomic and the controls are laid out to be accessible without shifting hand position.

The ARX 100 gets positive marks for its modular design. The ability to reconfigure the ejection port and swap barrels is a genuine differentiator that comes up often in discussions. Ergonomics and overall handling are frequently praised.

Accuracy at medium range is reported as solid, and reliability under varied conditions is generally spoken well of, with low malfunction counts cited by most owners.

The main criticisms center on two areas: weight relative to comparable rifles in the class, and limited aftermarket accessory availability compared to the AR-15 platform. Price is also discussed, with some users feeling the cost is high relative to what competing platforms offer. Maintenance is easier to some owners and more involved to others depending on familiarity with the system. Users who compare it directly to the AR-15 platform often note the trade-off: better out-of-box ambidexterity and modularity, but a smaller ecosystem of parts and upgrades.