I think there's no doubt it's "true", the main problem must be getting a perfectly windless day in the UK! No-one knows what is possible until you try yourself. I used to be able to hit a 6ft target at 100yds with a longbow probably every other shot ( no sights whatever ) with lots of practice and I was mediocre next to the good guys and gals. Cubleycat is one of many using airguns at the limit of their ballistics with great skill. My latest craze is bench rest air pistol at 60 yds, iron sights, 6" target. I'm not much good but that gives me a challenge.
Torrens