Per The Hollywood Reporter, Stallone took to Instagram late Tuesday night to announce that production on Rambo 5 was officially underway. To commemorate the occasion, the 72-year-old action movie star posted two photos of himself on social media. In the first, Stallone is dressed in Western gear for what looks like a costume test. As for the second, Stallone was wearing a variation on said costume while riding a horse, presumably during, or in preparation for, a night shoot.