Nope. NOT an April fools joke - The “ACCEPTABLE BARREL LIFE” wS ESTIMATED to be less than 100 ROUNDS.
Only ONE such rifle was ever built, to my knowledge.= Strictly an experiment.
COL Townsend-Whelen, in the late 1930s had a single-shot .30 caliber made on a .50 caliber BMG case, “necked down”, with no other change. - The rifle weighed about 30 pounds.
(The recoil was “said to be rather unpleasant”.)
Yours, TMN78247
I’m kind of surprised no one has mentioned 12 gage with sabot rounds.