S.C. Code Ann. § 24-13-440: Carrying or concealing weapon; penalty.

It is unlawful for an inmate of a state correctional facility or of a local detention facility to carry on his person or to have in his possession a dirk, slingshot, metal knuckles, razor, firearm, or an object, homemade or otherwise, that may be used for the infliction of personal injury upon another person, or to wilfully conceal any weapon within any Department of Corrections facility or other place of confinement.

A person violating this section is guilty of a felony and, upon conviction, must be imprisoned not more than ten years. A sentence imposed under this section must be served consecutively to any other sentence the inmate is serving.