Drew, at one time 2” guns had to pass the same proof as 2 1/2” guns. I think that is why that gun has a 1 1/8 ounce proof stamp. I sure would nit have shot any 1 1-8 loads in the 2” I had. Some of the factory loads would rattle your fillings. I can only imagine what a 1 1/8 ounce would be like.