I think today I may have been able to answer my own question. While visiting the state library in Nashville I took the opportunity to look up H.W. Bullock's service record. He was wounded in the shoulder with the ball ending up in his back near his spine. He was captured shortly after being wounded. Union doctors removed the ball from his back, but Bullock suffered a "violent hemmorhage from the wound in his back" and died on April 18, 1865. The record goes on to list his personal effects and states that his effects and body were sent back to Clarksville, Montgomery County, Tennessee to his father John Bullock (lists him as being related..not being father) and a T.W. Pettus. He arrived back here on April 21, 1865 according to the record. It appears that Capt Bullock is indeed likely buried there in the family plot with his parents. He just needs a marker now.