Need help learning about rifles. I have pistols down but no rifle experience. Is there any website to teach about different rifle types, scopes/sighting (like all the terminology and how to use scopes efficiently) oh and what does MOA mean. When people say 3MOA or 4? And also ammo sizes and lethality. I just bought a M&P15-22 and have the flip up mbus sights but also want a scope/red dot for long range shooting and don't want it to be in the way of the mbus if those are up. What is the difference with scopes/red dots/reflex/acog. I am determined to make a badass looking rifle and have it shoot good and far also. But I don't want to put no 200.00 scope on a .22 rifle u know. Thanks.