agency guns
In those days, firearms were retained at each individual park. A ranger was not issued a career long handgun, you got a gun issued at your posting, turned it in when you transferred, and received another when you arrived at your next assignment. I saw some really old revolvers in assorted park armories. Condition and type could vary depending on how much money each park mgmt team wished to spend on the Ranger Division. As the NPS is not solely a LE organization, but a resource mgmt agency that manages a LE function within its structure, LE often got the short end of the stick (budget). Often folks making such decisions had no LE or firearms background or training whatsoever. No surprise then when old guns get paired with hot ammo.
For the most part, the older guns were Model 10's in HB configuration, occassionally a M15 would surface. Those old K's were replaced largely by M19 and M66's. Eventually the Ruger Securities and the L-frames became fairly common, still all "park" owned. All that changed with the auto pistol program. Rangers received an issued auto pistol upon graduation, which one retained through their career, regardless of assignment.