Copper 45 acp bullet ???

Since you are looking for a light to medium target load, you can use any data for 200 grain bullets. If you are going to a maximum load, you would need to start at least 10% below max and work up to a safe load, the same as any other bullet. I use 200 grain lead, plated or jacketed bullets interchangeably with a target load of 4.5 grains of Bullseye.

The usual rule of thumb for loading copper plated bullets is to load them about half-way between jacketed and lead pressures. For instance if you manual says 5.0 grains of Bullseye for JHP and 4.0 for lead you should load them at about 4.5 grains. I did this with Rainier copper plated bullets and it worked very well for me.

The copper plating is softer than actual jackets, which are a low-zinc mild brass. I have always heard you should use lead bullet loads for them. Rainier Ballistics seems to say the same the same thing: their plated bullets may be used with any load intended for lead bullets. If all you have available is jacketed bullet load data, they recommend reducing the maximum by 10% for use with their plated bullets. You can read that recommendation here.

I don't know if all plated bullets are identical to Rainier or not? Obviously, if the plating got thick enough it might act more like a solid, but I don't think that is normal practice. They are only trying to get enough on to cut down on lead contamination, which is mainly caused by muzzle blast on the bottom edges of the bullet.

Are all other

I have used the Rainier bullets in my 44 and used my hard cast loads and couldn't tell the difference.
Back in those days I shot a lot and was shooting 100 yards with the 44, so not being able to tell the difference was a good test.
Today, I don't shoot the handgun enough to be able to to the same test. My shooting sucks!! I need to start shooting 100 rounds per weekend again like I did back then.