Bill,
It will depend on your paper which will add .006 to .008" to the diameter with two full wraps, you can size bullets as well with a lubesizer. I looked and could not find commercial bullets that I thought would be a good starting place. I thinking a custom mold, throwing a bullet around .479" or so and a heavy bullet(500 grains or so) is the way to start. You might look at the sights for an idea as to bullet weight, lots of height difference and likely a heavy bullet. Might ask on ASSRA if anyone has a mold of about that diameter, check ebay as well.