Re: USO SN-4
I've got a SN-4 1.5-6x with the JNG MOA reticle on my 16" .308 upper. Unless you are dead set on 1-4x you should check the JNG reticles(MOA and Mil versions available) before you order the circle chevron. It is outstanding - maybe the best CQB reticle out there. On 1.5 power it's almost like using an EOTech but on 6x it is fine and precise enough for easy hits at 600. With the reticle you can range and holdover very well. Of course any USO you choose will be tough enough to pound nails with...
Good luck,
Erik