Getting new sights for my remington 870. Remington says the vent rib size is 1/4 inch. Some of the peoples reviews in which I was browsing around looking for some good sights say that remington is actually a 5/16 size. Just checking from some of you that have ordered new sights. Turkey season is near and I dont need to order the wrong size. And which is a good adjustable sight? I was looking at the truglo pro mag gobble dot is this a good one, or do I need to lean for something else? I did measure and it did read 5/16 not 1/4 like remington says. I don't want to wrong size sight this close to season! Thanks