Re: You think your side arm is badass?
A howdah is the platform you ride on while travelling by elephant.
So you're up there, hunting with The Raj, and a wounded tiger starts climbing into the howdah. Your trusty Holland or Purdey double rifle is unweildy in those close quarters thus the howdah pistol. They are usually multi barrelled as taking the time to reload is not advised.
Be careful not to shoot the elephant or it's mahout as the pistols are noted for overpenetration. After all, if you kill the Raj's favorite hunting elephant or even it's mahout, you will not be invited back.