Aging plays a major part in “The Expendables 3,” which was once envisioned as throwback franchise for older action stars to flex their muscles once again, showing the kids how it’s done. In the four years since the original effort, creator/star Sylvester Stallone has started to consider his years, with mortality and retirement major themes of the movie. He also introduces a younger squad of mercenaries to join the fight, not only to add some fresh energy to the series, but to secure its box office future beyond the battle-weary bros who’ve already survived two installments. That’s not to say “The Expendables 3” isn’t rock-em, sock-em entertainment with explosions, stunts, and quips galore, but it’s a surprisingly reflective feature that still traffics in big dumb fun, daring to address the mileage on a few of its leathery stars. Read the rest at Blu-ray.com