well, I cured the low light performance issues with the scope.
I bought a Zeiss Dialyt 2-8x42 for a rifle but hadn't mounted it yet. I put it on the crossbow, calibrated it so the fifty yard aim point is the top of the vertical post and it's dead on at twenty with the cross hairs. Seems to shoot well.
Tried it last night and I gave up and went home before I lost shooting light with it. Much more precise in poor light now and it is plenty enough to use well past legal shooting time.
I think I may try a much cheaper scope when I finish the rifle project and need this scope, but it sure is nice for now. It'd be nice to find a BDC reticle that I can calibrate so that intermediate yardages are close enough.
