Yep
Hatcher's Notebook, 1966
https://books.google.com/books?id=yESNUKSg5aMC&pg=PA184&lpg“E.C.” blank powder burns with extreme speed…to give a sharp report when it is not heavily confined. An enthusiast once got hold of some of this powder, being familiar with “E.C.” shotgun powder…and loaded a bunch of shells. To try out his new load he got out his fine Lefever gun, and put up a target in the shooting gallery to get the pattern. There was a terrific detonation, and a big piece was blown out the side of the barrel near the breech, flew across the room and buried itself in a wood bench.
