Source: http://www.thefirearmblog.com/blog/2013/07/31/kaboom-223-wssm-6mmbr-disaster/ :

This post was written by Dr. Jim and Mary Clary.

Under most circumstances, shooters don’t have to worry about chambering the wrong cartridge into the wrong rifle. After all, the cartridges are well marked and we all know which rifle we are shooting on any given day. In many cases, incorrect cartridges cannot be chambered–larger cases will not fit in smaller chambers, for example. No problem! That being said, I can tell you that even an experienced, careful and normally safe shooter can make a mistake.

The following is an account of just such a mistake that could have resulted in death or dismemberment. Fortunately, the shooter was not hurt, but the rifle was completely destroyed.  […]