Ironraven-
Yup I saw a distinct difference in the M6 even with the "flip around" sights, presumably included to offset the issue you describe. So the varmint scope I sighted to the .22, and I shoot the .410 with the see through/traditional sights.

No problem, and like originally stated, this isn't designed to be ultra accurate, but rugged and "at hand", for critters, not defense. But with the scope, I improved my percentages.

And sotto, ditto, I grew up with a .410, easy to handle, did the jobs on the little dinners-to-be.