COLUMBIA, S.C. (AP) -- A man accused of abducting a Columbia teen last seen more than a month ago has pleaded not guilty to a federal ammunition charge.

Freddie Grant entered the plea in federal court on Tuesday to a charge of being a felon in possession of ammunition.

Gabrielle Swainson was last seen by her mother at around 4 a.m. on August 18. That month, Grant was charged with kidnapping the missing teen after her blood was found on duct tape near his home.

Authorities also found .38-caliber bullets and shells for a 12-gauge shotgun -- ammunition Grant isn't allowed to have as a convicted felon.

Authorities have said Grant had dated the 15-year-old's mother and had done yard work for the family.