These Varmint Grenade, made by Barnes are amazing. I am going to have to try them out in the near future 🙂
In the below video they fire one of them into a grape and the bullet completely disintegrates.
Barnes makes these in .243/6mm (62 gr), .22 (36 – 50 gr) and .204 (26 gr) caliber.
More on the bullet here.