I have a Trijicon RMR dual illuminated sight with a 9 MOA dot. Tried it on a Glock and ended up taking it off. So I tried to find a place where a 9 MOA dot would work well, and that place was on top of my dual buckshot/turkeyshot shotgun. 9 MOA is 3.6 inches at 40 yards - about the size of a turkey's head from the tip of the beak to the back of the head. I like a bigger dot for a shotgun. I tried a Delta Point Pro with a 2.5 MOA dot and that lasted about 5 minutes before I went back to the 9 MOA dot.

A 6 MOA dot will cover 2.4 inches at 40 yards. It should work well.

[Linked Image from i.imgur.com]
https://vcdl.org/