To shoot a s58 off ticket is illegal. The acquisition and possession of a firearm under s58 is for obsolete firearms to be owned as an ornament or curio. For a firearm to be used in anyway in the U.K. will place that firearm in a category requiring certification, in this case s1.

Should you be discovered shooting a s58 off ticket, you would be guilty of an offence of unlawful possession of a s1 firearm as the purpose you had that firearm at that time was not as an ornament or curio.