“I swinged it real hard. Or “I swung it real hard” ???? Spellcheck says that swinged is not a correct word and swung is correct.
“Swang” is used in the American south, particularly the Scotch-Irish areas of the Appalachian upper south. It’s not incorrect but is slipping into archaic status. It’s the simple past form rather than the past participle. It’s also commonly used in the north of England and in Scotland, unsurprisingly as that’s where it arose.
Oh, and “Scotch” is correct, too, by the way.