Ideal range to zero red dot on shotgun.

[swamp2]

i would never use a red dot on a shotgun cause it would cause you to get a higher cheek weld rather than using a standard bead sight or vent rib. and there is no optic shadow to tell if your looking through the center rather than canted.

Try it, you'll like it.

There are no downsides of the higher cheek weld.

A red dot is parallax free and is thus robust to alternate cheek/head positions and odd shooting positions. That's the whole point of a reflex sight, if you can see through the optic the slug will hit that spot. You comment about cant is thus completely incorrect. This is it's largest advantage IMO of a reflex type sight.

It will help most beginner to intermediate shooters (perhaps even some vary skilled ones as well) improve their accuracy.