The Excel Arms X-5.7R is an AR-style semi-automatic rifle chambered in 5.7x28mm FN and built from CNC-machined billet aluminum. It pairs an 18-inch barrel with a 6-position collapsible synthetic stock finished in black for a modern, modular profile. A threaded muzzle and picatinny rail keep it ready for common optics and accessories. 
 

Key Specifications 

• Brand: Excel Arms 
• Model: X-5.7R 
• Caliber: 5.7x28mm FN 
• Action: Semi-Automatic 
• Barrel Length: 18 inches 
• Stock: 6-position collapsible synthetic 
• Color: Black 
• Receiver Material: Billet aluminum 
   

Detailed Features 

• Threaded barrel accepts common muzzle devices for the 5.7x28mm FN chambering 
• Picatinny rail and added accessory mounting points for optics and rails 
• CNC-machined billet aluminum upper and lower for a rigid platform 
• 6-position collapsible stock adjusts length of pull for different shooters

Owners of the Excel Arms X-5.7R describe it as a solidly built billet rifle, with the aluminum receiver holding up well to regular range use. Reliability with 5.7x28mm ammunition varies more by ammo brand than with more common calibers, so some shooters recommend testing a few loads before settling on one for the X-5.7R.

The collapsible stock and familiar AR-pattern controls make the carbine easy to pick up for shooters coming from other AR-style platforms. The 5.7x28mm chambering keeps recoil light, which owners often cite as a reason it works well for new shooters or extended range sessions.

Because 5.7x28mm is a less common chambering than more mainstream centerfire rounds, magazine and ammunition options are more limited and pricier, and that is the most common complaint from X-5.7R owners. Those who already shoot FN 5.7x28mm pistols like the ability to share ammunition across platforms and see it as reasonable value for a billet-aluminum build.