Well,if a .36 colt used a .375 bullet & a .38 Special uses a .357 diameter bullet then logically there's a missing link somewheres that used a heel(.22lr)type bullet to shoot a .375 dia bullet out of a .357 case.Unfortunately my brain is stopped at ye olde .38/200 rounde.I canna' remember any more.
revolver bullets used to be outside lubed, like a .22 is. They had a reduced diameter "heel" on the bullet, like a .22 does. When they got enough comlaints about debris sticking in the lube, preventing chambering, they went with the bullet down inside of the case. that meant either smaller bores, or larger OD barrels, cylinders and frames. It was MUCH cheaper to just use smaller OD bullets.