A buddy of mine started reloading for his Remington M700 in .270; he saw a max load of 4831 powder in the manual and assumed that would be OK, so he STARTED with the max load. Well . . . the manual was written using H4831, and DuPont had just introduced IMR4831, which is NOT repeat NOT the same as H4831 - it's significantly faster.
It took both of us, working together, to open the bolt. AND THEN HE FIRED ANOTHER SHOT!!
After helping him open the gun
again, we dissected the problem - he was a bit put out when I explained about the different 4831s, and roundly cursed DuPont - deservedly, in my opinion - for introducing a powder with the same number as an old standard, but with major differences in performance.
There was no damage to the rifle - worked fine, headspace OK.
On another occasion, I was at the trap range when a guy blew up a Browning Citori - barrels were bent down from the receiver by more than 90 degrees, most of the chamber from the lower barrel was simply gone, and the sides of the receiver itself were bent outward. Never did figure out what happened there, as even a double charge of powder shouldn't have destroyed the shotgun
that thoroughly. (I think he got some sort of compensation from Browning, but don't know the details.)
Other than some minor cuts and scrapes on his left forearm and a few nicks on his face (he WAS wearing safety glasses) he wasn't injured.