Here's the largest center-fire rifle ever made, the .950 JDJ by SSK Industries.
Only three were ever made. This was the lightest, the carbine version, weighing in at 50 lbs. It shoots a .95 caliber, 2,400-grain bullet at 2,100 fps using 240 grains of powder, which generates 25,400 ft/lbs of muzzle energy and 277 ft/lbs of recoil energy.
Each round costs $40.
Thanks for the video, Rurik