While I couldn't download the photos,the ".380" is the official British name for the shorter, fatter .38 S&W cartridge,the one that their S&W Victories were chambered in. It is too fat to fit .38 Special chambers, Since this was their "official" revolver cartridge for the military,from the mid 1920's until the end of W.W. II,the New Services might have been reamed out a bit to fit.
They also bought New Services in .45 Colt,and ,.455 Eley,Webley will work in these,unless the headspace is way too big. They also bought a few New Services in .357 Magnum.
These guns were shipped in 1940,when there was a real fear of Operation Sea Lion(German invasion) becoming a reality,after the fall of France.
The Brits were buying up virtually any gun they could in America,including Colt Target autos,N.S. Targets and Shooting Masters were included-and SAA's! Yup,they cleaned out Hartford and Springfield(S&W) of nearly anything!! People here also donated guns of all types to the Brits(collection points at hardware stores etc.)
A fascinating scenario! 1)What "gun control" can do to disarm a nation 2) the slow sales of the New Service and the Single Action Army at this time,that is evident by the large number of these guns "in stock" at Colt. So,when a "Monday Morning Quarterback" denounces Colt for discontinuing the N.S. and SAA after W.W.II(and Colt did make many mistakes in the post war era!) here is tangible evidnce of those models slow sales,
I can't say for sure if the parkerizing was done in Britain during or after the War,but it never left Hartford with that finish,or with plastic stocks in 1940. Since the anti gun Brits,just heaved revolvers into wooden crates in the 1960's,after stamping on them "not english make",for export back to jobbers in the U.S.,many had dings and nicks-not from "combat-as these guns were held "in reserve and most never issued,as they were "not standard",it could have been parkerized by a jobber here, The plastic stocks were a common Colt factory replacement in the 50's and 60's!
This English abuse of fine weapons,by lack of any packing,is a bone of contention to some of us on the S&W Forum,as many fine .455 T.L.s and 2nd models were "vandalized".
The barrel markings and the text indicate it's chambered for the 38 special. I'm no expert on the goofy markings the Brits loved to stamp all over the fine guns we sent them, but I thought our 38 S&W cartridge was known as the 38-200 on their side of the pond.
You are correct: the 38-200 was the British service round of the WWII era, and is known over here as the .38 S&W. What surprises me is that this NS does appear from the pictures to be chambvered for the .38 special. Not common.
The .380 is a "3 decimal place" description of the caliber. You know the Brits, they gotta be exact! The .320 & .380 Revolver were originally outside lubricated rounds that had heel bullets pretty close to the diameters. The old .32 Colt and .38 Colt(short) were copied from them. Then we have the .450 Adams,.476 Enfield and .455 Eley etc.
I think the first U.S. handgun round to go out to "3 places" was the .380 automatic,but some called it 9 mm short.
Many Brits refered to any .38 as a ."380" and those anemic rounds would fit a .38 Special,where as the .38 S&W was too fat.
The .38/200 was,as was said,was the definition for the .38 S&W round with the 200 gr. bullet,that we called the ".38 Super Police" over here,where it was "invented" around 1920. Sadly,the Brits expected the hitting power of the .455 Webley with a 265 gr. bullet,both these rounds going a sedate 600fps! Couple this with the Hague & Geneva Convention "outlawing" lead bullets,the Brits went to around a 178 gr, fmj. that was even worse!
BTW,those "Battle of Britain" Colts are prized collector's items,but that gun looks like a post war parkerizing and plastic grip replacements.
My guess is that this New Service will shoot the old .380 Revolver round-but not the fatter .38 S&W or ".38/200". Or else it would have been over stamped "38/200". There was plenty of .380 revolver rounds around,and these would fit the revolvers chambered for the .38/200,lie the S&W Vicory models,but with a loose fit(possible case splts) in the chambers.