You cannot have certain arms items unless you have a firearms licence. You can have them if you are with someone who has a firearms licence. They are watching you and making sure you use the items correctly. You are not allowed to have a non-prohibited magazine or a non-prohibited part without a licence or supervision. If you break this rule without a good reason, you can get a fine of up to $10,000. This rule is part of the Arms Act 1983, which was changed by the Arms Legislation Act 2020. If you have one of these items, you need to follow the rules. You must have a good reason if you do not follow the rules. You will get in trouble if you do not have a good reason.