If I hadn't spent all my gun money on .38 S&W guns already, I'd snag this one, too
No real reason, I guess, except "the addiction" has many phases, doesn't it?
As far as ammo ID & gun caliber goes, here's some info: Webley designed a new revolver in the early '20s, seeking British Army adoption of a lighter, easier-to-shoot gun for recruits given quick training under wartime conditions. The cylinder was not long enough for the .38 SPL, but was for the .38 S&W, and the Brits considered the latter round decently effective in US police service. They boosted bullet weight to 200g to increase stopping power, on the "slow & heavy" concept.
I know that Colt called the .38 S&W round the ".38 Colt New Police," probably to avoid printing "S&W" on their revolvers
I'm not sure if the Brits were the first to load the cartridge with a 200g bullet & it was subsequently adopted by many US police depts., or if the Brits were inspired by the .38 "Super Police" cartridge in US police service. The Brits referred to the round as .380 calibre, .380-200, .380 Revolver, .380 Rimmed, etc. Initially a 200g LRN called the Mk. I, various elements of Brit Army voiced concerns about Hague Convention rules against expanding bullets, so they switched to the Mk II 178g FMJ. Both Marks had a "Z" version, which denoted either nitrocellulose or cordite loading, I forget which. (I can look it up if anyone wants to know.)
I've been playing around with loads for my 4 S&W Mods. 32-1 (2") and 4 Mods. 33/33-1 (4") 5-shooters in caliber .38 S&W, as well as for my tighter-chambered Colt Police Positive Special. With 158g LSWC at 710fps, or 200g or 215g LFN bullets at low-600s fps from a 4" barrel, the bullets track straight thru 6 gallon jugs of water and embed themselves in a 2x12 stop board. From a snubby, the 158g stuck partially in the board, IIRC, and the 200s LFP only dented the stop board.
From a 4" barrel, the 178g ball ammo drills thru multiple overcoat layers, a milk jug, starts tumbling & explodes jugs 2 & 3, and IIRC passed thru more jugs. (This coming week I'll write up those results from my notes.)
Although the factory 145g (Winchester) and 146g (Remington) loads are LRNs at a stately 685fps, this power level is kept low due to the existence of bazillions of old break-tops of weak construction. Loading manuals such as Lee 2nd and Lyman 49th make it clear that you can load to levels that approach low-end .38 SPL ballistics in modern, solid-frame revolvers. Certainly I'd be comfortable doing so in a K-frame that's in good condition. Pushing a 200g at around 700fps would create a fair-sized wallop on the receiving end. I keep my J frames down in the low 600s with 200g bullet, which was the vel of the original Brit service ammo.
The widespread popularity of the round in late-19th and early-20th centuries was partly due to its suitability for compact-framed revolvers with short cylinders, not to mention low recoil/report. Once you get up to K frame, though, it has no advantage over .38SPL, and its only advantage in J frame is the easy, full-length ejection stroke when it's time to reload
