I respectfully disagree. There are too many variables to say 20 sec is a long time, 30 maybe. But that maybe be from spotting the target by the CO, alerting the gunner and driver, the driver increases rev's (most likely not reving an engine to max under no load that is a bad idea dynamically for the engine), spin the turret till it's close via the hydraulic's and then hand cranking the turret to the target. If the target is moving the gunner needs to guestimate how much he leads the target and the gun elevation for long range shot. So 5 sec for the CO to alert the crew, another 5 sec for gunner and driver to coordinate the turret spin via intercom (foot tapes on shoulder wouldn't work), 10 to 15 sec to spin the turret close at 1000 rpm or idle engine speed and then 5 sec to aquire the target in the gunners sight and another 5 sec to guesstimate a lead. So that 20 to 30 sec maybe ok. Then this is repeated if the next target is outside the gunners sight angle.