does teh 308 model work with the bac thingie.  I right now have the variable IOR on my FAL.  Thinking of moving that suckler elsewhere and putting on a TA01B....

No the TA01 series does not have BAC which requires the reticle to be lit (like with the fiberoptic Compact, TA31 and TA11 models)  you dont seem to understand the concept of the BAC.  Id provide a link but i have to leave for work.

Bindon Aiming Concept

Some people can use the Bindon Aiming Concept with an unlit, fine crosshair reticle - those people are genetic freaks! BAC basically works when there is contrast between the reticle and your target. The more contrast there is, the easier it is to use this concept. Some ways of adding contrast are to make a thick post reticle, to illuminate the reticle, or to illuminate a thick reticle (triangle, post).

I do know people who can use BAC with an unlit, thin crosshair reticle. I wish I was one of them; but I'm not. I need an illuminated reticle and a somewhat coarse one at that before I can use BAC well. Since the TA01B is only illuminated at night and has a fine crosshair reticle, you will have to be one of the lucky few or it will not work for you - and by lucky few I mean I can count the people who can do this on one hand despite a lifetime of shooting.