USMCDADX2, a great scope, while new is expensive, but can be found used reasonably, is the 1.5 x 5 Leupold varix3, at 1.5 power, it can be used in the house, and of course once outside, the higher power is nice. It is a quality piece of glass, search on AR15.com, Swfa, gunbroker etc... I got mine for 175.00, because the previous owner did not mount it securely on a big magnum rifle, and it had bad ring marks, does not bother me, as long as the optics work.