I'd stay away from the TA01. It is calibrated for the .223 with the 55 Gr. ammo, which is very hard to match up with. The TA31 is pretty good, but not as precise as the TA01NSN, which has the crosshair reticle. So if you want more precision, get the one with the crosshair reticle such as the TA01NSN, TA31DOC, TA01NSNDOC.Black45 said: