I had a chance many years ago to put 4 or 5 magazines of the original 10mm Norma through a Bren 10 (I was shooting at the Huntington Beach pistol range, D&D was in HB, ran into their QC guy at the range)
Quite impressive - ballistics more like a .41 Mag than a .357 Mag. Not really any bigger than my 1911's - but I was too much of a "purist" in those days to consider a "crunchandticker" (Even Chairman Jeff's endorsement couldn't have swayed me)
Besides - other than the D&D QC guy and Sonny Crockett - I don't think anyone ever saw more than (2) magazines in the same place at the same time
Did wind up buying a 1076 several years later, had to handload to get anywhere near the Norma ballistics. If Santa were to put a Delta Elite under the tree I wouldn't turn it down...