Elmer Keith pioneered the .44 Magnum, but it never really caught on for police work. Regardless of what you see in the movies, most police chiefs or sheriffs would have a coronary if their officer was found to be carrying a .44 magnum, and sound reasoning dictated against that choice. The N-Frame revolvers are heavy, certainly heavier than a K-Frame revolver, And, they're big. If you go look in the front seat of a well-used police cruiser you're likely to see a worn spot in the drivers seat where the muzzle of the gun rests against the upholstery. An N-Frame is bigger than a K-Frame and sitting in a police cruiser is uncomfortable if the gun is too big. The muzzle touches the seat and the grip digs into your ribs, and after just a little while, it's uncomfortable. Damned uncomfortable.
Probably the very best cartridge that I've ever explored for rural police work is the old Colt cartridge, the .45 Long Colt. Every lawman from St. Louis to San Francisco carried one in the early days, and by that I mean the frontier times. The Colt Peacemaker and the .45 Colt cartridge were ubiquitous across the parries and the mountains of the west. Those long-barreled Peacemakers were great for horseback riding, but for police cruiser riding, not so much. Smith and Wesson still makes a double-action revolver, the Model 25, and I've always thought that a 4" Model 25 would be the bees knees for rural law enforcement if we could cut a hole in the seat to let the revolver ride naturally in the car.
In all my career, there is just one officer that I every heard about carrying a .44 magnum on duty. I never saw it, I just heard about it, and if I remember the story correctly, it went something like this:
In Toledo Parish on the west coast of Louisiana in the late '70s there was this young deputy. We'll call him Cowboy. Cowboy was aptly named. He had rodeo'd for a time. Cowboy stood about 6'4" tall, skinny as a rail and came to police work while he finished college. Like many of my generation, he had seen the Dirty Harry series of movies. Cowboy wanted to carry a .44 magnum, and he certainly had the physique for it, so he managed to acquire a 6" Model 29, and quietly started carrying it on duty. It looked natural on his tall, lanky body, and anyone who casually glanced at the tall lawman didn't notice the big damned revolver he was carrying, it simply looked proportional to his frame.
Like all young, struggling police officer/student/fathers, money was tight. One night, while doing a walk-through in a local beer joint, one of the patrons asked what he was carying. Cowboy told him and the patron offered to buy the pistol, right there, for cash, at a healthy premium over what Cowboy had originally paid for the revolver.
The money sounded good, so Cowboy unholstered the revolver, dumped the cartridges, and the deal was made, right there at the bar. Cowboy rolled the money into a roll, and dropped it in the holster. He finished his shift several hours later and went home.
The next afternoon, the Sheriff noticed Cowboy at roll call without a revolver in his holster. "Where is your gun, Cowboy?"
"What are you going to do if you get in trouble tonight on the side of the road?"
Cowboy extracted the wad of cash from his holster. "I figured I'd give him this, and buy my way out of trouble."That's the story of Cowboy and the .44 Magnum. I can't swear if it's all true, but that's the way I heard it.