UK-based engineer Tom Stanton has successfully built a trebuchet that can send projectiles flying at supersonic speeds. Stanton used the CNC mill, he had previously built at home to carve the piece and even redesigned them after stress tests exposed the weakness of his pieces. With the 22 pound (10 kg) counterweight, Stanton could hit the 394 miles per hour (mph) with his projectile. As he reached the 88 pound (40 kg) counterweight, the projectile speed reached 716 mph, just 51 short of the number, to match the speed of sound. In the video, the projectile reached 776 mph (1,248 kph) or nine miles per hour faster than the speed of sound.