I've used 115gr FMJ exclusively for years, but now I'm using 115gr plated bullets (from RMR).

I'm not horrendously surprised to see that there isn't much data our there on plated or cast bullets in this weight. At least not that I can find.

Any reliable source of load data would be appreciated.

I'm using Bullseye and Power Pistol powders.

I had this same question a few days ago. 5.5 gr of power pistol starting load.  Looks like most people stay under 6.0 gr.  Expect a nice light show.  I went to the range with 5.5 and 5.7 gr loads with magnum primers.  I'm going to stick with 5.5 for plinking.

This question comes up only a couple times a week.  The answers are always the same.

Here ya go.

From Berry Plated Bullets.

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.

Link.
http://www.berrysmfg.com/faq-q21-c1-Load_Data_for_Berrys_Preferred_Plated_Bullets.aspx
From Rainier Bullets.

Loading Data
We, at Rainier Ballistics, recommend using lead bullet load data when loading our bullets. There is no need for adjustment when using lead bullet load data. Our bullets are jacketed using an electroplating process and are softer than traditionally jacketed bullets; hence the recommendation to use lead bullet load data.

***If you only have access to traditionally jacketed load data, we recommend a starting powder charge directly between the listed minimum and maximum load, and you may use published load data found in reputable reloading manuals.

A slight roll or taper crimp may be used with our bullets;

Overcrimping plated bullets may result in decreased accuracy, and fragmentation of copper plating.

Link
http://www.rainierballistics.com/loaddata.php

Might be time for a Plated Bullet Load data Sticky?

Take this for what its worth , but this was a response strait from Alliant when i asked the same about plated bullets in 9mm and 45 acp with bullseye in perticular, i personally use 4.5 in 9mm and a plated 115 at the moment with no problems, little snappy

115gr lead

red dot            start 3.7     max 4.2
bullseye          start 4gr    max 4.5
unique            start 4.5     max  5 gr
power pistol  start 5gr    max 5.5

115gr jacketed

red dot             start  3.6     max 4.3
bullseye           start 4 grs  max  4.5
unique              start 4.5     max 5.5
power pistol     start 5.9    max 6.3

Thanks for the info!

THOSE JACKETED BULLETS .From rmr aren't the same load to jacketed  specs.........

Just got an email back from my "go to" reloading guru in AL:

This is a recipe that Alliant themselves recommended, back when I asked
them about plated bullets in 2001:

115 grain plated bullet
5.8 grains Alliant Power Pistol (6.2 grains max)
Any standard small pistol primer
COAL = 1.12-"

You can also substitute 4.3 grains of Bullseye (4.6 grains max) for the
powder charge.

In a nutshell, if neither lead nor plated bullet data is available, you
can take the equivalent FMJ load, and reduce the charge by 7.5%.    
Ranier Ballistics says you can use a 5% reduction as a guideline,
although I tend to be a bit more conservative.



This information is good to know because right now I don't have a powder measure. I'm using Lee dippers which tend to measure out a charge that weighs a tad lighter than the recommended starting load for a jacketed bullet (at least according to the Lee handbook and 9mm die insert).