Technically, you are correct in that you can own a black powder pistol as black powder weapons are not considered handguns and you are over the age of 18. See SC Code 16-23-10. However, it really depends on what you mean by the definition of “carry”. A black-powder pistol is considered a weapon. See SC Code 16-23-405. If by carry, you mean if you can legally own and fire a black powder weapon you are correct. This would be like if you were in a Civil War reenactment. However, if you carry the black powder pistol, as you would any other pistol, then it is illegal and you could be arrested, unless you have the proper permit. In South Carolina, you must be at least 21 years old to obtain a concealed weapons permit. The penalty for carrying a concealed weapon without a permit is up to $1,000 and/or up to 1 year in jail. S.C. Code 16-23-50. Additionally, the police would take the pistol away from you permanently. See SC Code 16-23-460.