The magnum 410 000 buck (approx 36 CALIBER) have a muzzle velocity of about 1150 fps... that is hotter or as hot as many handgun loads. Sure, some handgun loads are hotter but the 1150-1200 fps coming from a 410 double barrel shotgun is formidible and potentially very deadly.

And, yes as aptly noted, you've got to pattern your gun BEFORE you shoot it at any animal, especially one that has the propensity to administer cosmetic surgery upon your being.

Generally speaking 20-40 paces is the maximum distance I would shoot a big cat, like a mountain lion, with any buckshot. Slugs would be my recommendation for the 30 to 50 paces shots at a big cat, or at deer. I guess I would not use buckshot for deer.

Most buckshot even in 12 gauge 3 inch magnum loads are under 1300 fps. That is still hotter than most handgun ammo.

When I hunt in country where there are cats or bear, and when it gets too dark to see well, but I still have to walk thriugh the woods to get back, I usually pull the slugs out of my double and put two 000 buck shells in the tubes. Obviously in the semi darkness or darkness, no shot would be more than 30 paces and most likely more like CLOSE range. And with the inability to even see my sights the advantage of a pattern of 8 or 9 000 buck PER barrel is clearly obvious. Point and click! Boom. repeat. Boom.