Barrel regulation isn't included in the price of junk guns.

I might add that all the vintage English SxS's that I've owned had perfectly regulated barrels.

When aimed like a rifle off a rest all the O/U'rs I've patterned all shot at least a 1/2 pattern low with the bottom barrel at 40 yards...a few worse.

The two 1960 vintage Winchester 101's I own a 12 and a 20 are spot on at 40 yards.

When Beretta or Browning is confronted about it you hear the same song and dance as you heard.

Manufacturers know that very few people that will go to the length of testing point of impact on their guns.