Out shooting foxes for a farmer, Roy Lupton comes across all kind of wildlife, including deer and - he reckons - a yeti (we DON'T reckon). Well, there's one big lesson to learn and that's backstop - when do you shoot and when do you not shoot?br br It's the same message at Holland & Holland where we go for their stalkers' course. Instructor Chris Bird explains the basics of selecting safe shots.