Realistically Duncan, to get those group sizes with most rifles, people are mainly talking about from a bipod or other rest (sandbag etc) and prone or from bench/support. There are to many variables otherwise. The small group sizes quoted just give an indication of what the rifle, ammo, firer, combination IS capable of.
All of the long range corvids and rabbits I shoot with my CZ are from prone and bipod or other support, (over 150m) and any shots less than that, I will use a bipod where I can. This is for the simple reason- I am there to kill vermin, preferably with every shot taken.