"Once, while I was working in Switzerland, a Hell's Angel offered me a brand-new AK47, still in its greaseproof wrapping paper, for £300. He would have even thrown in a thousand rounds of ammunition for good measure. 'Here,' he said, 'try it out.' And so I did, firing at a railway sleeper maybe 60 yards away at the bottom of a quarry. The effect was astonishing. The bullets smashed the sleeper into two pieces that ended up ten feet from one another. So much, I remember thinking, for those Hollywood heroes who say 'ow' when they're hit."