Call it an unintended impact of September 11.

The thundering roar of parade cannons that used to make babies cry and tourists jump is less jarring now due to significantly tightened restrictions on what artillery can be stored on campus.

Before September 11, the cannons used 75 millimeter blanks stored at the armory on campus. Now Palmetto Battery is feeding 10 gauge shotgun shells into the parade cannons.

"All Army salute guns have gone to the 10 gauge shells since September 11," said Colonel Scoot Powers. "The issues with storage and security have forced us to adapt but, on the other hand, it is much less expensive and easier to use the shells."

The Citadel can no longer store ammunition on campus because of tighter security rules. The nearest Army base that stores such material is Fort Jackson.

Powers said the big booms will return on major weekends such as Parents' Day, Homecoming and Corps Day. On those days, the Commandant's Office will get the 75 millimeter blanks from Fort Jackson. In the meantime, the Corps and the public are adjusting to the change as yet another sign of how much has changed since the terrorist attacks of one year ago.