sss5358
I am sure that Cayugad will get here soon, but Dave has had a ton of experiance with a Black Diamond and my be able to help you right of the bat...
It it an XR or a regular BD? How many shots have you shot throught it? What was you most accurate load? even if it was not that accurate... might be a good starting place to begin to help.
Normally... and for most of the reports that I have read about the BD it is a really darn accurate rifle....
You said TC had it but do me a short favor look carefully at the crown on the barrel - does it appear to be uniform all the way around the muzzle? Maybe even compare to your other TC...
I am sure help will come...