Badge 851 is correct, the pictured lead semi-wadcutter hollowpoints in 158 grain weight and Plus-P flavor are known as the F.B.I. or Chicago load. They are still pretty good stoppers in spite of being fairly old technology. All the S&W brand ammo I shot in the late 1970-early 1989 period was accurate.
The Treasury load is a 110 grain jacketed hollowpoint loaded to Plus-P-Plus / +P+ velocity and pressure. They are pretty harsh to shoot, especially in a small frame revolver. There are no industry specs for +P+, and agencies that ordered it would ask for such-and-such a bullet at such-and-such a velocity; the ammo manufacturer would then load it and sell it to the contracted agency. Treasury loads weren't generally available in the retail market.
The day I was sworn in to my agency almost 30 years ago, they handed me a badly worn S&W Combat Masterpiece .38 sixgun, a badge and eighteen Smith & Wesson brand .38 Special 158 grain jacketed hollowpoint cartridges. I assumed the cartridges were to be used to check the sights on the guns. The armorer glared and told me that this was "the good stuff" and that six rounds went in your gun and the other twelve rounds went into your belt loops. We were to save our "serious" ammo for real police work. We would get sighted in and qualified with something else, which turned out to be cheap remanufactured low pressure 148 grain wadcutters, from the same stocks we had shot at POST. The S&W jhp ammo was indeed good, accurate and clean shooting. I bought a couple boxes on my own to check out.
I have only fired two makes of the treasury load; both were given to me by an Immigration agent that was a neighbor. His boss gave each agent a box of the hot stuff and a box of mid-range .38 Special wadcutters every month and the agents were expected to shoot them and bring the empty brass back. He had been shooting all his life and found the practice to be obnoxious as he carried a 2-1/2 inch Model 19. The treasury load really belched fire and thunder out of the snub's short barrel. He was delighted I was a shooter and that I thoroughly enjoyed making his loaded ammo into once fired brass Sometimes he brought me several of his fellow agents' ammo that also needed to be converted into once-fired brass, and I was very pleased that, in some small way, I was contributing to the security of the country by shooting up the ammo for the agents in order to free up their time so they could catch bad guys.
Imagine, free ammo!
One note here: The federal agencies that had the +P+ ammo made for them were told that the ammo was harsh and to shoot it in .357 Magnum revolvers, since it was really too hard for regular .38 Special guns.
My seven would-be deputy probates and I graduated P.O.S.T. in late December. My Sheriffs Office then prepared extra training to teach the rookies how we did it at our department. Well, we had to qualify. We had a very poorly ventilated indoor shooting range and as it was cold and snowy, the firearms Lt. decided we would qualify our Combat Masterpieces inside the dark, dirty range and passed out each of us a 50 round box of a commercial .38 wadcutter reloads from the same maker we had been given our police academy training ammo. It came in orange and white cardboard boxes, just dumped loose in the boxes, no trays; it was low budget stuff. So clean your gun well that night and we would shoot them first thing tomorrow morning.
I had saved my 500+ rounds of empty brass I had shot in the Academy as well as the little orange and white cardboard boxes they came in. I had tumbled and processed the brass, intending to load them with my home-cast double ended wadcutters, hoping I'd get some extra range time.
An idea plopped down in my brain. I checked a couple of my sources and decided to load up 2 50 round boxes with an artificial black powder simulant called Pyrodex. Pyrodex was wonderful stuff. Shooting cartridges loaded with it provided the "BOOM" of black powder accompanied with the big dense clouds of stinking smoke, just like black powder. Pyrodex wasn't corrosive, so shooting it in our Combat Masterpieces shouldn't hurt them. I did foresee an opportunity to generate some exitement and a bit of humor, so I loaded up 100 rounds with Pyrodex.
Sure enough, the next morning, the 8 recruits and the range master Lt. found ourselves in the basement range of the Hall of Justice, ready to qualify us with our new Combat .38's. The LT., not wanting to waste a lot of time, had us put up target backers on only 4 of the 12 shooting lanes. It looked like we would each shoot the course once and then go to lunch. I slipped my boxes of Pyrodex loads into the open case of standard practice ammo and drew my 2 boxes.
To make things even better, our Chief Deputy, a retired FBI man, snazzy dresser and a killer of many birds with shotguns, came down to watch the new kids shoot. He often shot with the new guys, offering to buy lunch for anyone who could beat his score. I was pleased to have an even bigger audience for my stunt.
First relay up. I'm pretty sure that John Salazar has a box of my super- smokers. The course was 50 rounds altogether fired onto 1 B-27 target at 3, 7, 15 and 25 yards, from kneeling, standing, sitting, weak hand, etc.
"Readyontheleft...readyontheriiiiiiiiiight...FIRE!" the Lt. yelled! We had an excellent firearms instructor at POST, a fellow named Dennis Tueller, who taught at Gunsite for Jeff Cooper, and this test was just childs play for us. Eight guns "snicked" out of their leather holsters and the shooting began, "BOOM BOOM BOOM BOOM thud BOOM thud BOOM thud thud BOOM!"
The 18 Pyrodex rounds were wonderful! Thick, dark gray smoke filled the bays. The exhaust fan didn't dent it It stunk. We were coughing and hacking. The LT was grumbling.
The first relay shot the rest of their rounds. Salazar could barely see his target at 25 yards through the smoke. We hung up new targets and took our places. This time it looked like Tom Florez had my psuedo-black powder rounds. "BOOM thud BOOM thud thud BOOM thud BOOM BOOM thud thud BOOM BOOM thud BOOM BOOM!"
Everybody was coughing and hacking then. Visibility wasn't 10 feet. We scored our targets while the chief deputy yelled at the Lt. about the cheap-*** crappy ammo he'd bought. LT. yelled back at the Chief that **** seemed to buy all they could get with the meager budget he had. They were cranky. They they both yelled at the rookie who had instead shot up all 18 rounds of the expensive Smith & Wesson JHP ammo we had been issued the day before during the qualification.
Our hands and faces were dirty. The guys complained about how much smoke and filth they endured and resolved to never shoot in the indoor range again because the ventilation seemed non-existant.
I told my classmates what had just transpired. I pointed out that the Lt and the Chief were now busy yelling at each other instead of yelling at us. They laughed. One of them bought my lunch that day.
I still have those 18 rounds of Smith & Wesson 158 grain j.h.p. cartridges sitting around here somewhere.
