Scott Eastwood: Longest Ride On A Mechanical Bull

Scott Eastwood held on for way longer than 8 seconds while riding a mechanical bull at a San Diego bar ... so long it's actually pretty impressive.

Clint's son has had some practice ... he played a pro bull rider in the chick flick, "The Longest Ride." And, of course, his dad played a cowboy in a ton of his flicks, so it's no surprise really Scott's a natural.

If the movie thing doesn't work out ... bull ridin' might be another calling.