Lifted this image from the Gun Shop and Range Stories group on Facebook. At first the shooter said it was caused on round 3 of some type of Remington 150gr factory loads. Apparently it was confirmed it was a very hot hand load.
I don't hand load, so I don't know how hot you need to make that round that it blows the upper in half and split the BCG like a peeled banana, but it looked like a fun picture to share.