I presume by "T-series" you are referring to the High Powers made during WWII by John Inglis of Canada, and bearing seria numbers running 1TXXXX, 2TXXXX, 3TXXXX, etc. These are by all accounts excellent guns, though all parts do not interchange with FN manufactured guns. I cannot compare them for you with modern production BHPs, but compared to milspec P35s they are about as good as they get.