Are there or are there not thousands (if not millions) of .38s in circulation that will accept a .357 cartridge. Yes or no?
Revolvers made for .38 and .38 special that will accept and fire a .357 cartridge are hardly a century old nor are they “defective.” They were made for a long time and guns don’t age much if given even minimal care. Or simply not used and abused. Be aware of the danger. If you lose an eye or the use of your hand you probably won’t care how “minimal” the chances were that it happened to you.