This just across the NPS wire–from a Gettysburg press release.
Bob Jones of Gettysburg with a bullet in a tree on Culp's Hill
Gettysburg, Pa. — With Civil War commemorations planned throughout the nation for the next four years, employees at Gettysburg National Military Park just got a reminder that the past is still with us. Park maintenance employees were cutting through a fallen oak tree on Culp’s Hill when the chain saw hit bullets.“Culp’s Hill is one of the areas on the Gettysburg battlefield that saw intense fighting in July 1863,” said Bob Kirby, Superintendent of Gettysburg National Military Park. “One hundred years ago it was commonplace to find bullets in Gettysburg trees but this is a rarity today.”The discovery was made on August 4, 2011, as maintenance employees cut a fallen oak tree that was resting on a boulder next to the Joshua Palmer marker on the east slope of Culp’s Hill summit. Two sections of the tree trunk where the bullets were discovered have been moved to the park’s museum collections storage facility. As a relic of the Battle of Gettysburg, the tree sections with bullets will be treated to remove insects and mold and then added to the museum collections at Gettysburg National Military Park.
Due to the steep slope, most of the fallen tree was left in place and will remain there, according to National Park Service officials.
A number of witness trees on the Gettysburg battlefield have been well known and frequently pointed out for years during battlefield tours. In addition, National Park Service employees often identify previously unknown Witness Trees during preparatory work for battlefield rehabilitation efforts, a program where the park re-opens historic meadows and farm fields to restore the historic integrity of the 1863 battlefield and to improve the visitors’ understanding of what happened during the fighting of the epic Civil War battle.
Mysteries & Conundrums 
I’ll bet the chain saw needed a new blade after this. Do I see that the bullet was cut in half?
Could the actual concessional impact sounds be imprinted within the rings of the witness trees, just waiting for the right technology to extract them and hear it. Like a record cut. We now know for instance that plants of all kinds and probably trees respond to music in their growth. So much more the dramatic impact of the sound of 150 cannons blasting away preceding Pickett’s charge or the 100 union cannon responding. The sap within the rings could absorbe the explosions, and like a true witness tell us the real story through sound!