I bought a catalyzer with Bark Modules.

3* - The Toxic Catalyzer bullet sound is pretty puny.
4* - The Virulent Catalyzer bullet sound sounds really loud and POWERFUL!
5* - The Biohazard bullet sound is exactly same as the Toxic catalyzer 3* - puny!

Could it be that you accidentally got the sound files mixed up for the 4* Virulent Catalyzer and the 5* Biohazard?!

It sounds ridiculous with the Biohazard being a large gun making the same sound as the much smaller Catalyzer.

A purely aesthetic bug, but a bug nonetheless.

~Z