You are correct, the Sinclair is gen. 3. At this point, I do not see myself shooting NRA Comp. Mainly I want to shoot at informal shoots and practice on my range. I want this to be fun, not a rigid by the book deal. May change my mind later. Anyway, you have provided me with the type of info that I need. I looked at the Centershot website and the picture is not real clear. For starters, I will probably try both the Harris HBRMS and the Sinclair.