Shared from Zite WHAT'S A CARBINE? We use the term "carbine" throughout this piece to refer to both TrackingPoint's AR weapons and to AR-15s in general, but the word might not be familiar to a lot of folks. By the strictest definition, a carbine is a rifle with less than a "full length" barrel; what "full length" means can vary by platform. All carbines are rifles, but not all rifles are carbines. The US Army's M16 rifle (which is itself an AR-15 variant) has a standard barrel length of 20" and is considered a full-size rifle. TrackingPoint's AR-15s use shorter 16" barrels and are thus considered carbines. John Hames shared with you: GUN Linux: On the range with TrackingPoint's new AR-15s ...