The Beeman Kodiak is the elephant gun of spring piston air rifles. In .25-caliber it produces more energy at 50 yards than most Magnum air rifles do at the muzzle! But it's very heavy and produces quite a kick. In fact, it takes a lot of practice to be able to consistantly hit the bullseye. Mine shot with 30 lbs-ft right out of the box. After several years of use, the muzzle energy has dropped to 26 lbs-ft, so I guess its time for an overhaul.
One of the big advantages of .25-cal is the size of the wound channel produced compared to lesser calibers. This means your shot doesn't have to be quite as accurate, which means great leathality at greater range. And this has proven true in the field. But, of course, .25 pellets are heavy--and the heaviest of the them--the Kodiak pellet--has the best penetration by far over lesser weight versions--but the added weight means less range. Still, at 30 lbs-ft, I was still able to zero at 45 yards. See
http://www.velocitypress.com/BeemanKodiak.shtml for a complete test report.