Due to German protests in 1938, the 200 grain .38 lead bullet was replaced by a 178 grain jacketed bullet, to comply with the Hague Accords re bullets in civilized warfare. By WWII, Commonwealth forces were using the FMJ rounds. The reduction in bullet weight was probably due to jacketed bullets having greater bore friction than lead bullets. Thus, the same velocity could be maintained with jacketed bullets. If there is any other reason for reduction in bullet weight, I haven't seen it mentioned. Some S&W revolvers actually had bullets stick in the bores in RAF target shooting. I read this in a UK gun magazine. I think this was because some .38 Special barrels were mismarked and were used on .38-200 guns sent to the UK. A member here posted that he has a .38 that has just a .356 bore diameter. On the other hand, his gun was re-worked by Parker-Hale or Cogswell & Harrison to .38 Special after WWII and may have had both the bbl. and cylinder replaced. So, I'm not sure what that tells us. Most such reworks left the .38-200 barrel in place, just reboring the chambers to accept the longer .38 Special ammo. It is more likely that some barrels were bored on the tight end of permissible specs and that they may be marginal for use with low velocity FMJ loads. I have never heard of this with Enfield or Webley .38's, just the wartime S&W guns. Over 568,000 were supplied to the Commonwealth nations, and most must have been okay, or we'd have read more about the issue and the British govt. would have raised heck over the matter. Also, it seems odd that the matter arose with RAF target shooting teams after the war, during the 1950's. Maybe they had some lots of ammo that had slightly oversized bullets or were loaded too lightly. But Enfield and Webley guns probably do have slightly wider bore specs. If anyone reading this has one and can "slug" the barrel, please post your findings. That said, assuming that the guns and ammo had the right specs and functioned as they should, was the .38-200 an effective defense or military round? I read, I think in Gen. Hatcher's writings, that a cop in the US shot a fleeing thug in the back with a .38 S&W chambered gun using the US version of the 200 grain lead bullet. This ammo had a wider profile bullet nose than did the more tapered UK ammo. The idea of the 1929 UK load was to cause the bullet to tumble in tissue, causing greater wound damage. So, the loads are not the same despite having lead bullets at the same velocity, or very close. The shot felon had a bullet dug out of him that measured some .75 caliber! Maybe it'd expanded on bone? This was at a range of 75 yards. Wow! The late David W. Arnold, a South African gun writer and cop (in Rhodesia) told me that he'd fired .38-200 guns at an old British Army greatcoat, and that the bullets did not penetrate the coat! But on another board, someone shot those bullets into wooden planks and got full penetration and they sailed through an old coat easily. I read an account by a British officer who shot an Italian soldier in North Africa in the back with a 38. The man did go down and was taken to an aid station with the Briton, who had also been wounded. This was at El Alamein or another battle in that area. They waited for hours for surgery, the Italian in great pain. He finally died. Not a swell example of the low velocity .38's power. But it did penetrate deeply enough to cause a fatal wound. It is interesting to note that when Churchill formed his Commando units in 1940 to raid German lines, he insisted that their handguns be the Colt .45 automatic! Did he realize that the .38-200 was too weak to be a good combat round? He personally carried a .45 and offered one to his police bodyguard, who declined, as his issued Webley .32 auto was lighter and handier. Churchill had bought a .45 auto in 1915 for his WWI service, and presumably considered it as the best available battle handgun. Personally, I lack faith in the .38-200, with either lead or jacketed ammo, and also disliked the .38 Special M-41 ammo I had to carry as a USAF cop in the 1960's. Our NCOIC went off base with unit funds and bought some .38 Hi-Velocity ammo (.38-44) and I felt better with that. I sometimes carried a .45 auto instead, but our stash of ,45 ammo was old and had been much abused by repeatedly running it though magazines over the years. At another base, we had newer .45 ammo, and I had full confidence in it. My brother had an AD with a S&W .38-200. This gun had a six-inch bbl. and was probably made in 1940-41. He used commercial US .38 S&W ammo, I think Remington. The bullet struck the end of a copy of, Haven & Belden's , A History of the Colt Revolver, 1836-1940. The book was lying on a shelf about ten feet away. The bullet penetrated about an inch in the tough, good weight paper. I imagine that penetration in flesh would have been greater, but that was still poor performance. Anyway, that about covers my knowledge of the .38 S&W/.38-200 load. Please add your thoughts. If you've shot any dogs, coyotes, raccoons, etc. with that round, what was your experience?