FORT JACKSON, S.C. -- Fort Jackson has called up dozens of Reservists to instruct Soldiers in training during the summer.

The Army is legally obliged to provide one drill sergeant for every 20 Soldiers, but that ratio is increasingly difficult to reach during the summer because of seasonal surges in Initial Entry Training Soldiers expected to arrive at Fort Jackson, said Lt. Col. Scott Ward, the post's mobilization planner.

"We run on 53 drill sergeants, and that's nearly a battalion's worth of drill sergeants," Ward said.

Active Duty Operational Support (ADOS) orders will bring 57 drill sergeants to Fort Jackson, with the majority of them having already arrived and completing orientation. Ward said most of these Reservists will be dispersed throughout Fort Jackson's Basic Combat Training units. Four female drill sergeants are scheduled to arrive for the summer.

Post Command Sgt. Major Kevin Benson said the shortage is the result of an inability to graduate drill sergeants at a rate necessary to meet the surge in Soldiers in training.

"The augmentation of our reserve drill sergeants is the short-term fix for the gap in drill sergeant coverage," Benson said. "It's great to have them. They're fulfilling the role we need them to fill, at the right time and the right place."

It helps that most of the ADOS drill sergeants require little schooling.

"Most of these people are already drill sergeants, and are certified in other areas," said Sgt. Maj. Timothy Webb, operations sergeant major.

Ward said the biggest challenge is finding enough drill sergeants to meet the needs of Fort Jackson's female population. The post not only trains almost 70 percent of the Army's female Soldiers, but all of the Army's drill sergeants, as well.

"This is the only drill sergeant school in the Army right now," Ward said. "They have to produce the drill sergeants for Fort Jackson, Fort Sill, Fort Benning and Fort Leonard Wood. So everybody that gets a drill sergeant badge here will be broken up and sent to the four installations.

"Even though we produce all of the drill sergeants here, we don't get them all," Ward said.

ADOS orders end Sept. 30, but Benson said it is doubtful that Fort Jackson will meet 100 percent of the mission's requirements.

"One hundred percent is the goal," he said, "but you're never going to get 100 percent. Part of that is the available number of sergeants out there, both male and female."

He said female drill sergeants are in the shortest supply, and that many of the women who would ordinarily fill these spots are currently fulfilling missions in the Middle East.

"We can accept that we'll not be at 100 percent, but 90 percent is our operational goal throughout the summer," Benson said. "We've already achieved that."