I've found that hand rolled rolls are the best to search. I've found everything from a British penny to Canadian King pennies to 4 wheats (including a 1916) in one roll. The worst to search are the sealed rolls that have shiny pennies at each end, with one end an obverse and the other end a reverse. Dirty penny rolls are usually no good. Sealed rolls are hit and miss.
CWR has been pretty bad to me for cents. I've also only found 2 Bufs and 1 war in all my CWR nickels. CWR dimes are the only rolls that have given me silver. BWR quarters are the only ones that have given me silver.
if you check my post from a couple weeks ago and what I got in nickel bank rolls. I have to lean towards them being you know that they are not already searched by someone