I have a NF Competition 15-55x52 (2014 version). What a wonderful piece of glass! I got it to put on the 6mmBR I am taking delivery of this coming Friday, but in the meantime I have been using it on my 10FCP HS Precision at 300 yards. It's way more scope than needed at 300. I have found I shoot best with it on about 30x at 300 yards. I have shot it some at 55X and that is just too much magnification for that distance. I end up chasing the red dot in the middle of the target, and it pulses with my pulse. If it's hot, the mirage is a killer. When I get a chance to shoot the 6mm at 600 yards it may be more useful, but for now I have put my 5-20x50 Vortex Razor HD back on the .308, and the NF will go on the 6mm when it arrives.