I thought the science behind it is basically he make bullets from a material that is harder than what meteorite composes and then condense it to only a sugarcube size, improving it's penetration and density. The enemy ship's barrier is designed to block energy-based attacks, not physical. Additionally, the armor in the enemy ship is thought to be strong enough to endure meteor strikes, but those white dwarf bullets are claimed to be stronger than meteorites.
So really, this case actually doesn't really have much science behind it other than "type/element advantage" and can be summed to "The Hero used White Dwarf Bullets on the Enemy Ship, it's Super Effective!".
![Big grin :D :D](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)