Hydra Shok is ammunition made for various calibers by Federal Arms Co. The single largest difference between Hydra Shok and any other ammo is the post design. Hydra Shok is an ultra hollow point in its basic form, but the post design allows greater penetration with unmatchable spread and impact. In short hydra shok is the PREMIER man killer round

A bullet with a hollow inside and serated tip that, upon impact with a viable target, gets twisted inside out, forming a very large mushroom shape, thus increasing the caliber of the bullet dramatically. This results in either a HUGE exit wound, or it stays in the body, causing certain death. Very expensive. 25 bucks for a box of 20 rounds. Really good for self defense though. Really good if you intend to put someone down with only one shot.