I was issued a Model 15 and later as an Air Force OSI agent, a Model 36, 3 inch heavy barrel. The Model 15 was a little harder to conceal but it was a shooter. The GI 38 Special rounds were ball, but pretty hot. Working protection details, we shot often. The Model 36's for investigators had a short service life as the full service load was hard on the frame and cylinder. The Model 36 was replaced by a chopped, Detonics-sized .45ACP, which was replaced by a Beretta 92, then the Sig M11.
I knew aircrews who carried 2-inch Model 15's and Airweights. During Vietnam combat operations, the life support equipment rooms for aircrews had metal drums that were cut in half and supplied with a metal stand, and filled with .38 Special ammo. Pilots would load their revolvers at a clearing barrel and then could take as much ammo as they thought prudent by the handful. Some of the pilots I knew had bootleg Browning Hi Powers and no one seemed to object.