The major effect in bullet 399 is "toothpasting", i.e., a small amount of the lead core has been squeezed out of the jacket base like toothpaste from a tube.
(The major effect in bullet 399; is toothpasting; ) (a small amount of the lead core; has been squeezed; out of the jacket base like toothpaste from a tube)
The major effect in bullet 399 a small amount of the lead core
is toothpasting has been squeezed
out of the jacket base like toothpaste from a tube