From a Chuckhawks article:
This tip flattens enough to cushion the primer of the cartridge in front of it in the magazine during the acceleration of recoil, yet returns to its original shape instantly thereafter.
https://www.chuckhawks.com/leverevolution.htm
It also talks about the accuracy and ballistics, but I just mentioned that the rubber was supposed to be safer in a tube mag according to the marketing of it. Yup, I only shoot lead flat nose ammo and lots of it with no issues, and not about to change anytime soon. But hey, thanks for the reminder.

