Unclenick the alloy used is plain clamp on wheel weight. As far as diameter goes I will find out in the morning. I do not have a micro meter.
My dial caliper says .460
Average weight is 395 grains give or take a couple of tenths. All were between 394, and 396 grains. Most were 395 and some change.
I will load some up and shoot them tomorrow. I am going shopping with my wife tonight so I will not be able to do any work on the bench.
No matter how many times you do it and nothing happens it only takes something going wrong one time to kill you.