Outer's "Foul Out" electrochemical bore cleaner. It uses reverse electroplating to remove every last molecule of lead from your bore. And it will not harm your bore in any way.
They're a bit pricey, but once you've used one, you'll wonder how on earth you ever got along without it.
It will also remove copper jacket fouling. Completely!! Your bore will look like it just came from the rifling machine.
IMHO, the Outer's isn't just the best way to go, it's the ONLY way to go. Everyone should have one.
(BTW, I am NOT employed by Outer's)
If you think a mighty military force is expensive, wait 'til you see what a weak one costs.