FN America FN 15 Rifles are based on semi-automatic, direct impingement platform for wide array of cartridges (5.56x45mm, .223 Remington, and .300 AAC Blackout - 7.62x35mm). This FN 15 rifle series is a versatile one that can be used in target/competition, tactical, and collector applications. Hard-anodized aluminum is at the core of FN 15 rifles. These rifles have flat-top receiver that feature a M1913 MIL-SPEC rail at the 12 o’clock position. Chrome-lined barrels are available, whose length vary from 16" to 18".