> yes I know it's a vague term but you also know what I mean don't @ me.

Our world is filled to the brim with vague constructed terms to solve for a problem, not for a clean categorization. The assault-style category is a desire to lump all the guns that multiply too much the assailant's power. It's not about a certain bullet type, or a specific barrel length. If it's too good at doing a mass shooting, it's assault-style.