gnu,
    Farmers don't have a "right" to own small calibre rifle. You have to apply for a firearms certificate, which in these touchy - feely days, is next to impossible to obtain.
    In my years on a farm we shot most of the foxes at harvest time with shotguns, because -

a) A shotgun certificate is much easier to get than a firearms certificate.
b) A moving target like a fox is bloody hard to hit with a single shot rifle, the spread of shot from a half choke shotgun barrel is much more effective.