***I can’t think of a powder you can double load in 223 or 5.56 and not overflow the case.***
How true! Someone probably grabbed the BULLSEYE instead of the IMR 4895 or IMR 4350.
I knew a guy who used W/W powders... W/W-231 for very light loads in .44mag, but mostly in his .45acp. W/W-296 for heavy loads in his.44mag.
Well, the containers looked identical if you didn't check the labels...
He loaded up some .44mag with about 29gr of 231 (IIRC, about 6 gr made for a nice, light load)!
When he fired one of the rounds in his Super Redhawk, it backed out the primer and locked up the revolver. Later on, he tried shooting some of those rounds in his S&W Model 29... Blew the cylinder apart and took the topstrap off!
Rile #1, NEVER reload cartridges when distracted!
Mark