This article explores the legal and administrative challenges associated with prohibiting firearms based on their appearance. The article begins by discussing recent events in Tasmania that put the spotlight on laws prohibiting certain firearms following this approach. It then examines the legislative context of Tasmania's Firearms Act 1996, including the development of gun control laws. This is followed by an examination of the challenges faced and identified by other jurisdictions in enforcing comparable laws. The most notable challenge identified is the inconsistency in prohibition arising from subjective decisions about a firearm's appearance. Finally, the article puts forward two possible public policy reasons behind the decision to enforce a prohibition of firearms by appearance. Whilst there is considerable literature on the broader debates around gun control and the effectiveness of Australian gun laws, there is relatively little literature that examines the interplay between legislation, administration, and policy.