When faced with large, dangerous game set on ending your life before you end theirs, there really is no substitute for raw power. That’s a fact that African big game hunters throughout history have recognized, and reflective of this are the huge, cannonesque rifles they took with them into the brush. Some of the most massive and impressive of these were the weapons in various incarnations of the 4 bore caliber, named for being roughly the diameter of bore slugged by a round lead ball weighing one quarter of a pound. Later centerfire nitro 4-bore cartridges fired bullets as heavy as 2,000 grains (0.286 lbs) as fast as 1,500 ft/s. Ian McCollum of Forgotten Weapons puts his shoulder on the line shooting a single-shot blackpowder centerfire 4-bore rifle under the watchful lens of a high speed camera, capturing the rifle’s tsunami-like recoil in slow motion detail:

Ultimately, the 4-bore rifles didn’t lack for power, but were cumbersome to carry, and due to their large bores actually possessed inferior penetration against thick-skinned dangerous game when compared to their smaller nitro magnum counterparts, such as the .505 Gibbs and .500 Nitro Express. As a result, the huge 4 bore rifles remained for the most part curiosities only, although their existence is a testament to their owners quest for maximum power.