Basically, the main categories of firearm that are still allowed in the UK are shotguns, long barrel revolvers and small calibre rifles. They're almost exclusively used in rural areas (vermin, hunting, etc.).
It's often the case when you hear of firearms related incidents, that the stolen shotgun (or whatever) gets tracked back to a farm.
I'm guessing a large part of that depends on how you define 'varmint rifle'. To a lot of people, the AR-15 is a varmint rifle, and I'm going out on a limb and just guessing that it's either very difficult or impossible to get a license to own an AR-15 in the UK.
As for the definition I grew up with (e.g., rimfire .22 and slightly higher power centerfire bolt actions,) my understanding is that, for the most part, those things are still accessible in the UK, if one jumps through the appropriate hoops.
Thank you, we have similar notions of what a varmint rifle is. My somewhat fluid ordering of rifles is: varmint -> plinker -> hunting -> assault -> anti-materiel.
If your description is accurate, (and I have no reason to believe otherwise) the answer to my original question is "farms are a bad example and are simply a manifestation of legacy licenses." All of the other examples were categorical concerns
My original thought, as pertaining to farms, was just that they're traditional shipping hubs. Lots of packages (feed, seed, grain, machinery) come in, and lots of packages (livestock, meat, produce) go out.
If I were looking for a non-descript place to traffic guns through, I could do worse than a farm.
