First off, the screws and pegs that were under the factory installed "red dot mount cover plate" were the correct ones for this 509 ACSS Vulcan red dot sight. The factory cover plate screws stick out the required .110" below the "RMR mounting plate" which is included with this red dot sight. The second thing I want to mention is its "co-witness" with iron sights. The Springfield factory available accessory sights "Delta Point PRO Height U-notch" sights, for the Echelon series and XD series give a nice (but low) 1/8" co-witness with this red dot sight. I like this myself, as they do not block the view threw the red dot sight. As far as ease of acquiring the "dot/chevron" with this sight, I imagine the 250 MOA circle will help, but I already have a good presentation with "Iron sights/red dot sights" (from years of use) but is still reassuring to see it as I am presenting my pistol to target. I really like the "Chevron/dot" and I find it worth the price of admission. To sum up, it's a good sight and I would recommend it!