Whoever writes MMurders doesn't seem to have a very good idea of how life in the country is lived: there is no way a policeman would accept the idea of a shotgun (however legally owned) being kept in any way other than in a securely locked gun safe, which would have to be bolted to the floor or wall.
My husband has a shotgun for pigeon or game shooting, and won't even let me know where he keeps the key for the safe.
These details are checked by the local police every time a gun licence is renewed, usually including a visit to the house.
Bah!