In 1908, after eleven castings of the first model of The Rattlesnake, Remington substantially reworked the design. He worked for several weeks to improve the symmetry and movement, and he was very pleased with the new version. In a February 8, 1908 diary entry, he wrote, "Worked all day on 'Rattlesnake' and think my modeling has greatly improved." Nearly three inches taller than the first version, with a smaller base, changes to the model included tucking the horse's forelegs and straightening his rear legs, increasing the tension of the animal, and thrusting the rider forward to be a part of the dramatic sidelong motion. While the riders in both bronzes are wearing chaps, note there are several changes in the details of the rider's gear in the later cast, as well as a change in the color of the patina. Only about 20 castings of the larger version were cast during Remington's lifetime.