I have a single action Colt revolver. Dropping the hammer on a live round is not possible because the cylinder will no be perfectly aligned. Plus my Colt ( model 1851 ) has a half cocked position that locks the gun up. Bottom line is the hammer has to go all the back to turn the cylinder completely into proper position. Then the only way to release the hammer is to pull the trigger. He is BS’ing.
Please see 23 and 32.