When the Dixie Light Artillery was disbanded on October 4, 1862, 32 of its members were reportedly transferred to the Purcell Light Artillery. Peter S. Carmichael's book in the Virginia Regimental Histories Series is indeed an excellent source on the battery's personnel.
The battery brought four Napoleons and an estimated 89 personnel to Gettysburg, including the following identified individuals (the source is Carmichael's book unless otherwise noted):
Bradford, Henry C., captured in Pennsylvania and held prisoner until March 1865.
Brown, Valentine, Jr., wounded in the head and shoulder.
Broy, William P., present, buried John A. Weaver on the battlefield.
Callaghan, John T., Private, present (Confederate Military History, Extended Addition, vol. 4 (Virginia), p. 785).
Carter, Charles, wounded in the thigh.
Drewry, Albert Sidney, present, promoted to quartermaster sergeant on June 12, 1863 (Confederate Military History, Extended Addition, vol. 15 (Texas), p. 378).
Farrar, James William D., deserted in Pennsylvania and captured.
Gay, Decatur W., wounded.
Gutridge, Henry, probably present, "present on every roll including final muster."
Hackman, Benjamin F., captured July 7 at Williamsport, MD.
Hammond, Mabery, gunshot wound left arm, captured in hospital near Gettysburg, exchanged September 1863; surgeon William A. Greene of the Sumter Artillery operated on Hammond on July 3 (The Medical and Surgical History of the War of the Rebellion, part II, vol. II, Surgical History, 1877, p. 557).
Holland, A. G., present (Confederate Military History, Extended Addition, vol. 4 (Virginia), pp 935-936).
Jackson, John W., deserted in Pennsylvania and captured July 28 by 8th Pennsylvania Cavalry.
Mahoney, James, shell broke his left ankle.
McGraw, Joseph, Captain, commanding officer, lived in Sharpsburg, MD before the war and was a teamster. He commanded an artillery battalion at Appomattox. Moved to Brooklyn, NY after the war and disappeared after trauma over the death of his son.
Price, William Andrew, wounded.
Sindlinger, John Henry, deserted, captured July 14 at Falling Waters, MD.
Weaver, John A., killed July 3, buried on battlefield by William P. Broy (Weaver had served with the Dixie Light Artillery).
On the first day (July 1) at Gettysburg, the battery was positioned on Herr's ridge near the Chambersburg Pike, firing upon the Federal First Corps. On July 2, it was posted on Seminary Ridge but not heavily engaged, only occasionally dropping a shell among Federal skirmishers. It took an active part in the grand cannonade on the afternoon of July 3.