The mighty "Victory" model produced during World War II would be the place to start when considering the revolvers that could have armed pilots from 1950 to 1975.
The various branches of service also ordered batches of additional revolvers from Smith & Wesson throughout the time period you specify. Some were special lightweight aluminum alloy, some even with aluminum alloy cylinders. Most of these post war guns appear to look like models sold commercially. The post war military acquisition of Smith & Wesson revolvers could be the topic of a very interesting book. There's folks here on this forum who know much more about it than I do.