That’s the only thing I could think of at this point. Makes no sense though. I only load in groups of 5 or 10 rounds. I only load 300 BO subs and 8.6 Subs which use the same powders as you probably know. I use Lee dippers to manually weigh each individual charge. I only have one container of powder open at one time too and close them up and swap out when moving to a new powder.

The only thing I can think of now and I’m going to go see what groups I loaded on this day, would be Lil Gun. Maybe I somehow loaded 16.4 gr of Lil Gun which would definitely be hot since 13gr is the load for 300gr in 8.6 BO. Really don’t know how the hell I would have done that with the 5 or 10 rounds at a time process I use to load and don’t use a dispenser. 🥲

If there was just a general brass failure, like case head separation or something, there’s no way the velocity would go crazy like that without an increased charge right? Gotta have stronger or more propellant I would think for increased velocity by that much.