The boom times for military contractors may be coming to an end if the Obama administration follows through on plans to cut back on outsourcing defense jobs to the private sector. During the previous decade, the Department of Defense, under President George W. Bush, doubled the contracting out of responsibilities to companies, at a cost of $400 billion. But a new plan says the Pentagon intends to reduce outsourcing back to pre-Bush levels, when about 26 cents of every defense dollar was spent on contractors. The rate currently is nearly 40 cents.