Zathras wrote: owner.
The information I've read suggests the air rifle would be more than sufficient at close quarters on a trapped Mink, though I do take your point and will consider my position on this.
of course it is, it will even dispatch a fox in a trap, although it's not the done thing, but here's the difference, a fox in a trap will lay down like a dog and be quite calm when you approach, they stay put even with the barrel of a gun poked through the mesh to within an inch of their head, dispatch is quick and non distressing, however a wild mink does not act like that, it's more like a DEVIL, hissing,jumping,snarling, the trap if not pegged down would very easily move around, as soon as you go near it this will get even worse, now you need to try and keep everything steady whilst you place that one shot, it's not quick and certainly distressing to the animal, more times than not a 2nd or 3rd shot is needed, so yes an air rifle is powerful enough to kill, but as the old saying goes, get the right tool for the job
a decent air rifle would probably cost upwards of £200 plus
a shotgun license £50
a second hand 410 £100
pack of 25 cartridges £6
plus you get the added bonus of being able to walk around your woods with a shotgun shouting "get orf my land"