Say, Carpediem!
What exactly do you plan to hunt for?
You can duplicate factory muzzle velocity and energy using cast b ullets in the .30-30 Winchester. That caliber was used to take one of the largest grizzly bears in the record book.
Most of the other non-magnum .30 caliber cartridges can be loaded up to probably 80% of factory muzzle velocity and energy using cast lead bullets. .300 Savage, .308, .30-40, .30-06, etc.
And last, but not least, the mighty .45-70 was used with lead bullets to take every game animal in North America before copper jacketed bullets became the rage.
What is it you want to do?