The FN 15 M4 Military Collector is a 5.56x45mm NATO semi-automatic rifle from FN America, built to military M4 specifications. It has a 16-inch chrome-lined, button-broached barrel with a 1:7 twist and an A2-style compensator. Weight is 6.60 lbs and the adjustable six-position stock brings overall length between 30.50" and 34.20". Part number 36318. 
 

Key Specifications 

• Caliber: 5.56x45mm NATO 
• Barrel Length: 16 inches 
• Capacity: 30+1 rounds 
• Weight: 6.60 lbs 
• Overall Length: Adjustable from 30.50" to 34.20" 
• Finish: Black (receiver and handguard) 
• Manufacturer: FN America 
• Model Number: FN 15 Military Collector (Part No. 36318) 
• Safety Type: Ambidextrous 
   

Detailed Features 

The chrome-lined barrel handles high round counts without losing accuracy and simplifies cleaning. The A2 front sight and adjustable rear sight give reliable iron-sight capability, which is useful for collectors who want to keep the rifle mil-spec without adding optics. 
 
The six-position adjustable stock accommodates different body types and situations. Hard-anodized aluminum upper and lower with synthetic furniture -- the build uses the same material specs as issued M4 rifles, which is part of what makes this a genuine collector piece and not a cosmetically similar clone. 
 
The ambidextrous safety selector works for both left- and right-handed shooters. Ergonomic magazine release allows quick reloads under pressure. 
 

Usage Scenarios 

For collectors the military heritage and matching specs are the main draw. Competitive three-gun or tactical course shooters will find the accurate barrel and adjustable stock useful. For home defense the semi-auto action and 30-round magazine give a capable tool in a familiar platform.

The FN 15 M4 Military Collector in 5.56 NATO draws positive feedback overall, with the military provenance as the main talking point.

Owners consistently mention build quality and materials fidelity to actual military specs -- not just the appearance, but the underlying construction. Accuracy and handling get good marks, with the adjustable stock allowing comfortable shooting across different shooter sizes. The rifle is often described as a versatile platform between collectors and active shooters.

Price comparison is the most common point of friction. The FN 15 sits above many other AR-platform options, and buyers debate whether the military pedigree justifies the cost over a similarly-specced but less storied build. Most who buy it feel the quality backs up the price; those who pass usually cite budget constraints rather than capability concerns. Customization -- adding optics, grips, and rail systems -- is a popular discussion topic among owners who want to extend the platform beyond its mil-spec configuration.