They may have been straight before you bent them. Bending them just made them shoot where you wanted them to. It's very easy to look down the bore of a barrel and tell if it's straight or not, by looking at the light rings that show up in the bore when the barrel is pointed towards a light source. If the series of rings are truly concentric then the barrel is straight. Making it "not straight" may be what you're doing, thereby making it shoot where you want it to.

I'm no stranger to shotgun barrel bending. But, when you've spent a lifetime shooting shotguns as I have and have never seen a gun shoot flat on which you were looking down the rib, it makes you question whether all these guns over all those years were "not straight", as you suggest.

Regardless, I agree that bending a barrel slightly can yield satisfactory results in moving the pattern up or down (in the case of a S X S). We just don't agree about whether or not those barrels were straight to begin with. I say the majority of them were.

Long ago a gunsmith friend showed me a way to accentuate those rings by cutting off a 20 gauge shell and removing the primer. Then inserting it in the muzzle of a 12 gauge like you were 'loading' it toward the breach end. When you point it at a light source the rings are starkly evident.