Mounting optics on the 15.25 inches of top rail you get with the Rogue bullpup chassis has been a challenge for me. I found that the reticule needed to sit up high, higher than I'm used to... finding the eye relief sweet spot was also a challenge. I tried several different combinations and the one pictured below seems to meet/exceed my wants and needs. Magpul MBUS - Gen II, LaRue Tactical LT608, Aimpoint CompC-2X 2MOA, EOTech FTS 3X magnifier - Gen II. * The MBUS required some work with a file to fit... this was an easy modification. I am able to co-witness the MBUS through the Aimpoint and I will eventually have an Aimpoint Comp M4s for my bullpup.