Sir Skrapwelder is indeed correct in his rules references. Though I suspect that Mr Cortese was thinking along the lines of using his trusty shotgun or military rifle - please excuse me if my assumptions are incorrect.
The auld wargaming adage of levelling ones rifles at a charging foe works well enough on a battlefield where the distances involved allow for aimed volleys as the natives close the gap over the period of a minute or two, no doubt uttering bloodcurdling cries as they do so.
In the confines of a skirmish game, however, the distances are so much shorter, as is the length of a turn, so it would be a very quick witted chap indeed who could get a shot off with a rifle at a man dashing just a few yards to contact. Perhaps that should become a talent? (scribbles furious note)
In conclusion, and unless Sir Charles informs me otherwise, you cannot get a shot off with a two-handed shooting weapon in the turn that your target moves into contact with you.