I think Brunswick puts "real" cores in the 12 lbs.+ balls, and also into some overseas 11 lbs. balls, too. You might check their website, in the pro shop section is a complete RG numbers and core shape overview.

Any other manufacturer only has them in 14 lbs.+ balls, as far as I know?
--------------------
DizzyFugu - Reporting from Germany
Confused by bowling? Check out BR.com's vault of wisdom: the FAQ section

You really have to go ball by ball and company by company.  Most of Brunswick's balls have dynamic cores (though not always the same cores) in lighter weight balls.  See this file on the Brunswick site.

Storm uses a lightbulb core (I think) in their lighter weight balls, even the high end ones, if available.  I'm not sure about Rotogrip or Ebonite (I think they use the lightbulb core, too), if you see a large change in the core numbers, that probably means some kind of switch.  Pancake cores are typically in the 2.66+ RG range with 0.010 or so diff.  Numbers like 0.035 and 2.6 are not usually pancake cores.

SH