That's Awesome! I've seen that before! He's shooting the wild cat cartridge .577 T-Rex. Claimed to be the "most powerful" sporting type cartridge in the world. Supposedly more recoil than any of the Weatherby Super Magnums and the 475 A&M Magnum! Ouch!!!
I used to participate in the Guns and Ammo forum in the old days of the interwebs. One of the members told a story about how he was out shooting prairie dogs for some ranchers in Colorado one day. Since he was in the middle of nowhere, he always took a bucket to take care of business, should the need arise. Well, the need arose, he took care of business and left a number 2 in said bucket. Well, he's sitting in the back of truck, popping prairie dogs left and right and accidentally places his braked, high velocity rifle directly over the "bucket of hud." The muzzle blast blew everything straight into the air and he was left covered in doo-doo for his long ride home.