[gigster]

.380 is essentially a short 9MM. No workie in .38 cal. He be dead.

[alpo]

Be very careful if you reload.
A 9 mm bullet is .355,.356 inches in diameter
A .380 is the same diameter
A 38 Special is .357, so a .380 bullet would go down the barrel if the cartridge fired in the derringer.
A 357 magnum is the same as a 38 Special, .357

All of these bullets are within a couple thousants of the same diameter

A 44 magnum is really .429 inches in diameter