I decided to order a Vortex red dot scope/sight from MidWayUSA after reading some good feedback on them. I have never owned nor used a red dot of any kind really. I would like to know how they are effectively used, what range of effectiveness/accuracy do they usually have with a 1x type and how are they at shooting accuracy over "xx" distances versus close range? I guess my basic question would be better asked; will they be accurate at 100 yards as much as they are at 50 yards? Are they like scopes and have to be boresighted at specific ranges?