My grandfather was a brewmaster for Pabst, which somehow got him the free retiree beer Miller's Olde English 800, when Miller started making Pabst products under contract when Pabst virtually folded into nothing but a holding company/brand with no real breweries.
The 40oz size was convenient for boiling bratwurst with pepper and onions, and didn't use up any of the more drinkable beer in the hosue.