S.C. Code Ann. § 25-1-2770: Number of votes required.

No person may be convicted of an offense, except as provided in SECTION 25-1-2735 or by the concurrence of two-thirds of the members present at the time the vote is taken.

All other questions to be decided by the members of a general or special court-martial must be determined by a majority vote. A tie vote on a challenge disqualifies the member challenged. A tie vote on a motion for a finding of not guilty or on a motion relating to the question of the accused's sanity is a determination against the accused. A tie vote on any other question is a determination in favor of the accused.