They ruin everything.
(youtu.be)
The things that hold the targets are very expensive. The ceiling also is not meant to take sustained damage. The bullets are supposed to go into the rubberized substrate at the end of the range. Most people shoot towards the range. A 7" ar47 pistol kicks like a mule and the stupid nigger was trying to rapid fire it without controlling the muzzle. This caused all of his shots to keep going upward until his entire mag was emptied into the ceiling rather than down range.