I was honorably discharged in 1979. The Air Force used Model 15 .38 Specials up to the early 1990s, I've been told, 10 years after the 9mm Beretta was adopted.
I heard of a doctor in the 1st Gulf War who was issued a Model 15, holster, belt and box of cartridges as his defense gun. The M9 9mm was in high demand by front line troops; quartermasters apparently figured that medical personnel would never have to use their sidearm so they got the "leftover" .38 Special.
I used to work with a guy who carried a Model 15 in South America, setting up a radar site, in the late 1980s. He said the same thing: the M9 9mm pistol went to troops likely to see action. His crew weren't expected to use their sidearm, so they were issued .38s (and M16 rifles).
I've been told by people that seem to be in the know that the military no longer has .38 Special revolvers in inventory. I've been told that they were all crushed and sold for scrap metal.
Makes me sick!