Begin by making bullets by hand, then with machines, then acquire entire factories. Expand into making guns, tanks, planes, and even nukes. Research new products, faster and cheaper ways to make them, and better methods of making money. Enter the stock market to raise capital, buyout rival companies, or perform market manipulation. Lobby the government for fewer regulations, better contracts, and more demand for your products. Turn the entire economy into a weapons making machine, making you ludicrous amounts of money.