For West Mercia, 'Closed ' means the firearm can only be used on land deemed suitable, so it has to have been inspected by an FEO and viewed as safe for the calibre requested. However, you may also need to show the need for a calibre e.g. if the permission is only for vermin, they may only clear it for up to .223 even if it is safe for .308, because you don't need it cleared for .308 'cos you don't have permission to shoot deer! We have recently managed to get a few new permissions which has meant that our FEO is having to criss-cross half the county and peer over hedges looking for enough landscape to use as a backstop! If the land was cleared some time ago for a smaller calibre than you want to use e.g. cleared for .243 and you have a .308 (and you have permission to shoot deer there) they don't have the man power to revisit so won't reclassify the land, meaning you can't shoot there until you have an open ticket, or apply for a variation for another rifle.