Do you mean eotech red dot sight? If so stay away from them and go aimpoint all the way. Palmetto state armory has Black Friday deals on then going on.
I've had the EOTech 512 on my shotgun using 3 1/2 inch Hevi-Shot Dead Coyote "T" shot loads for 3 years and never had a problem. In fact it's held it's same zero all this time. It works great in red and green lights.