Uh. Are you referring to CIB vs Armour in the miniatures tabletop (which is what I am reasonably sure Gamgee was talking about out) or CIB vs Armour in the WH40kRP supplement that should be discussed here?
If the latter, I'm afraid I don't have it, which makes me sad, but I would expect it to be terrible against vehicles but pretty solid against Carapace or Astartes War Plate.
If the former, then I'm pretty sure you take the CIB to eat infantry, not to crack Leman Russ frontal armour- or possibly any vehicle armour at all. Not looking at the codex right now, but isn't it str 3?
The CIB in TT is Str7 Ap4 Heavy 3, or S8 Ap4 Heavy 1 Blast Gets Hot, depending on what mode you fire it on.
Edited by bogi_khaosa, 03 July 2014 - 04:33 AM.