Sorry if this has been answered to death, but I could use a little help:

I have a AR10A4 carbine.  I want to go the ACOG route.  I believe there are eye relief issues with the TA01B.  It looks like I need to go the TA11 direction.

Will the BDC be effective as the TA11C was designed to be mounted on a carry handle and was calibrated with a 20" barrel?

I think that the TA11E is what I am looking for, but I think that I can get a much better price on a TA11C and I much prefer donuts to chevrons.

Thanks.

Just like the TA31 ACOGs, you can just change your sight in procedure to help you match the trajectory the BDC was designed for.

I think I understand it now.  The BIG BDC chart was a bit hard to understand for this newbie, but is clearer after a another read.

I think I am being too concerned about the BDC anyway.  I want the ACOG for more than the BDC anyway.  I think that the BDC should be in the general area anyway.  After all, targets are awful hard to see and hit accurately at 600 yd.

Thanks for the information