Hodgdon load data on the internet is a very reliable source.
Found at:
http://data.hodgdon.com/main_menu.asp
They manufacture the powder .... who would know more than them?
Here is what Berry's has to say:
"Currently published load data is limited to some calibers by Accurate, Western Powders and Hodgdon. We are working with these companies to get data published for all of our bullets.
We recommend using hard cast load data or start with mid-range jacketed data. Make sure data is below 1250fps unless you are using a Thick-Plated bullet that we list a higher max velocity for like the 9mm 124gr HBRN-TP that
can be shot to 1500fps in open class guns like a .38 Super. Keep in mind that since our plated bullet has the same pressure curve as a hard cast bullet, the published cast data will be very close to what you will get with our plated bullets. If you use Jacketed data with our plated bullets you can get from 5% - 8% increase in velocity using that data.
Other than the data from Western and Accurate for the 9mm, .40S&W and Hodgdon .40S&W there is no printed data available."
Also:
"Plated bullets occupy a position between cast bullets and jacketed bullets. They are soft lead, but have a hard outer shell on them. When loading plated bullets we have found best results using low- to mid-range jacketed data in the load manual. You must use data for a bullet that has the same weight and profile as the one you are loading. Do not exceed mid-range loads. Do not use magnum loads."
Straight from the horses mouth, so to say.