In the 1960s smoothbore tank guns were developed by the US, the Soviet Union, and later by the experimental FRG MBT-70 project. High-precision smoothbore tank gun barrels were perfected by the US Army’s Weapons Laboratory at the Watervliet Arsenal based on a pair of patents by inventor Albert L. de Graffenried, US3020786A ELECTRONIC TOOL RUN-OUT INDICATOR FOR USE IN DEEP BORING OPERATIONS, Filed July 20, 1960, and US3,217,568 DEVICE FOR CONTROLLING DEEP BORING OPERATIONS IN A ROTATING OBJECT, Filed May 25, 1962. More than 20,000 tank cannons were manufactured by the Watervliet Arsenal for the US Abrams M1A1 tank using de Graffenried’s patented high-precision manufacturing inventions.