These are S&W revolvers chambered for the 38 special.
Here's one of the S&W revolvers I inherited chambered for .38 Special. Since it doesn't have the model number stamped on the yoke so I believe this is a Chiefs Special (model 36) produced between 1950 - 57. At some point in the gun's history someone bobbed the hammer, probably to make it better as a pocket gun.If they are chambered in .38 S&W Special, they will chamber and fire .38 Special, .38 Long Colt loaded with .357-.359" lead or cast bullets, and .38 Short Colt loaded with .357-.359" lead or cast bullets. .38 S&W and .38 Colt New Police are a different diameter, and won't chamber in the .38 S&W Special.
Post some pics and let us see them.