Well the Crack would be almost instantaneous did he mean the crack of the bullet, or the thump of the report from the weapon being fired as a the 7.62 mm round has an approx. muzzle velocity of 2800 FPS or 854 MPS and there are 5280 feet in a mile means the round would strike target at 2640 feet at that short range the crack and thump would be pretty much concurrent. so any one in the immediate area of the poor unfortunate who has just been slotted would have little or no time to differentiate the two sounds, and would most likely be more concerned about finding cover, before attempting to locate the shooter, by which time the sniper would have probably moved anyhow. Dunno about psy evals for snipers, not aware of it being the practice in the Brit military, certainly not in the RAF Regiment at least. but these days, because everyone must be wrapped in cotton wool and protected from perceived mental stress, I expect all sorts of psch evals are done. One has to remember that Snipers , or at least good snipers, are a special breed of person, usually very very calm, and very very dedicated, I would assume that anyone not fitting a psch profile in the job description, would be weeded out at very short notice, as the instructors are snipers them selves, and know what to look for, and how to identify at a very early stage in the training, if a prospective sniper will actually be suitable for that role.