Board Thread:Questions and Answers/@comment-5522245-20150902070838

In the paragraph below, what is the last line meant to refer to?

Miscellaneous: Reloads every 1.25 sec, tiers 1-2 have darts, 3-4 have blades. Pierce is 20/30/40/40 and layers stripped is 2/3/4/5, respectively. Only final tier can pop lead.

Is it referring to the sun beams or the blades? Whenever I add blades, I still hear the sound of metal hitting another metal, so I assume the blades aren't doing anything to the lead bloons. 