The actual person whose rifle barrel exploded was unharmed and posted the aftermath pictures the same day on a shooter's board.
Correct you are. If I am not mistaken this is the second post to FR. The first time this circulated was several years ago. No matter, the guy was fortunate.
I was involved in an incident of a 175mm round prematurely detonating in the tube of a gun (not a howitzer) in Vietnam. The crew survived, but with ear problems and minor cuts from shrapnel. The lot of fuses that had been put in the round had a manufacturing defect. I wish I had some pictures, it looked similar to this, just with a barrel that was 31 feet long. (I was a mechanic and had a new tube installed and the gun was firing again within 48 hours. Support maintenance flew out to inspect the cradle and recoil system, but there was nothing wrong with it)