D.C. Mun. Regs. tit. 24, § 2343
2343.1 A person issued a concealed carry license by the Chief, while carrying the pistol, shall not carry more ammunition than is required to fully load the pistol twice, and in no event shall that amount be greater than twenty (20) rounds of ammunition.
2343.2 A person issued a concealed carry license by the Chief may not carry any restricted pistol bullet as that term is defined in the Act.
SOURCE: Final Rulemaking published at 62 DCR 9781 (July 17, 2015).