Load to Jacketed Data
Plated bullets, especially in revolver applications, should be loaded to jacketed data.
Plated bullets are not jacketed; and plated bullets are not bare lead either. Here's the first thing you need to understand: Copper has more friction as it slides down the barrel than lead. A plated bullet – although not jacketed – has copper dragging against the barrel; therefore, its friction coefficient with the barrel much more closely resembles that of a jacketed bullet than a lead bullet. So it follows, that it requires more propellant to overcome this friction than it would if the bullet were lead (I have load data proving this). The concern with using lead data is that it is possible (admittedly not likely) to stick a bullet in the bore if it is loaded on the extreme low end of lead data. And this is why I recommend using jacketed data.
There are others who will recommend using lead data; and they would be wrong, frankly. Their logic is based on their fixation on the fact that a plated bullet, if driven too hard, can experience plating breakdown. But to retreat to lead data for the sake of this rare phenomenon (basically only applies with 357/44 Mag, 10mm) is an extreme over reaction. This approach is just doesn't make sense. The much more logical approach is to use jacket data (to alleviate the possibility of a stuck bullet), but to simply be aware of the possibility of plating breakdown, and not drive them too hard. Those in the load-to-lead-data camp are doing so to alleviate something that might happen (plating breakdown), while ignoring something that always happens (copper to barrel friction). It just doesn't make sense.
Admittedly, this debate may be one mostly of academics. For starters, there is a lot of overlap between lead and jacketed data anyway. And in semi-autos, it’s less of an issue. But in revolvers – with the barrel/cylinder gap bleeding off gasses – the danger of a stuck bullet can be very real. Some plated manufacturers recommend loading to lead data. And I believe they are making the same logic error and/or are listening to their lawyers. At the very least, they are oversimplifying the matter because they don’t have the time or inclination to give the explanation I have just stated above.