The 2 Bore Rifle, popular in the 1800s, during the Victorian Era of British exploration and hunting of Africa.

Back then, there was only blackpowder, which deflagrates, that is, burns slower than the speed of sound, as opposed to modern smokeless powder, which detonates. Thus, in a well made firearm of strong steel, there was little chance of overcharging it.

Next to a 450-400 Nitro Express. Both elephant guns. Not that you should hunt elephants. you shouldn't.

The cartridge next to a .45-70. he 2 bore fired a 3600 grain bronze or lead solid. 3600 grains is half a pound. The charge used by hunter Sir Samuel Baker was 270 grains of powder. This is about half the charge the rifle can take without taking too much of a beating.

The .700 nitro express on the left for comparison. The .700 nitro can penetrate some tanks.

Here the rifle is charged with a full 500 grains of pyrodex powder and fired by a man not nearly heavy enough to manage it and who also does not lean into the recoil properly, hence the hilarity.

https://www.youtube.com/watch?v=1RIT5KloknI