The Spikes Tactical ST-15 is a mil-spec AR-15 built on Spikes' forged receiver set, known for the brand's distinctive skull lower logo and solid mil-spec construction at a competitive price. Type: Rifle Action: Semi-Automatic Caliber: 5.56x45mm NATO Capacity: 30 Year introduced: 2006, USA Weight: 62 oz Overall length: 32.5" Status: Active Intended use: Tactical, Home Defense