The ATACR Riflescopes are designed to maximize the potential accuracy of semiautomatic and bolt action rifles while also offering the revered bomb-proof durability Nightforce optics are known for. They feature a one-piece tube precision machined from a solid bar stock of 6061-T6 aircraft-grade aluminum alloy. The tube is two to three times thicker than riflescopes of a lesser quality, resulting in less overall stress, greater thermal stability, a consistent zero and a virtually impervious shield for the precision optics within.