A man in Poland has built the world’s largest working revolver, according to Guinness World Record. The weapon, a Remington model 1859, was built by Ryszard Tobys, of Piotrowo Drugie, west-central Poland. It took Mr Tobys around 2,500 hours to construct, since most of the parts had to be built by hand. The revolver, whose chamber holds six 136 gram bullets (4.8 ounces), shoots with great accuracy at a range of up to 50 meters.
Unfortunately, it doesn’t look like they provide any info on velocity or energy delivered to the target. I’m going to guess the velocity isn’t very impressive anyway. A high velocity bullet that large would have absolutely immense recoil, beyond what is even seen in the video.
However, we can compare this 136 gram bullet to other calibers we know. A 230gr .45 ACP round weighs 15 grams. So this revolver fires a projectile over 9 times larger than a .45 ACP.