Long actions have been used for short action rounds. Namely one famous but missed example is the M24 Sniper Weapon Systems the US Army fields. They are Long action rifles chambered in 308Win, due to the Army's desire to upsize to the 300 Win Mag when the rifle was being copied from the M40 Marine Sniper Rifle also a Remington action, but in this case a short action.
Currently Rick, the current record with a 50BMG using a MacMillian TAC-50 rifle ( the C15 per the Canadian Forces ) is 2,430 meters or 2,657 yards by Rob Furlong. The shot had a flight time of about 4 seconds over the mile and a half distance.
Shamefully both him, Arron Perry (who had a 2,310 meter hit) and the rest of the unit were accused of something they never did and were forced out of the military shortly afterwords. Why because it was politically incorrect for Canadian Troops to kill anyone anymore apparently. And these fine men paid the price for it .... but that is enough ranting.
Dimitri