Recently built my dream SPR around a Colt A2 Lower and a PRI MK12 Mod 0 upper, I love this thing. I am not the best long range shooter and I need to work on a lot of fundamentals such as follow through etc. But nonetheless I am very happy with this gun so far. Here are a couple of videos and pics featuring the "build".
Oh I know the rings are on backwards
IMG_6358 by 556 Channel (HD), on Flickr
IMG_6329 by 556 Channel (HD), on Flickr
IMG_6320 by 556 Channel (HD), on Flickr
Oh I know the rings are on backwards
IMG_6358 by 556 Channel (HD), on Flickr
IMG_6329 by 556 Channel (HD), on Flickr
IMG_6320 by 556 Channel (HD), on Flickr