Here's a gun question:

[hardluck]

145. Been struggling with a response

Not sure I understand your distinction between legislative and legal definition. A legislative definition, as contained in a statute, is a legal definition. It is controlling in the jurisdiction at issue. To the extent the definition is vague or ambiguous, the trial court, using the rules of statutory interpretation, can interpret the statute based on extrinsic evidence, for example, the legislative history. That trial courts interpretation is binding on the parties to the litigation but has no other effect. It is not precedent and is not binding on any other court. To the extent an appellate court interprets a definition in a statute, it may be binding, if not dicta, on lower courts, but only persuasive authority in other courts.

If there is no legislative definition, and a definition is relevant to the action, eg in a contact dispute where a definition is relevant to whether there was a breach, and where the term is ambiguious, then the parties can submit evidence as to the term and the court can make a ruling. But that is only binding on the parties to the case and has no other effect.

Not sure where a court would be ruling on the term "assault rifle" as it is not a defined term by statute. I guess in a breach of contract/fraud case, but that definition is only binding on the parties.