NEW YORK (AP) — Hollywood's summer at the box office isn't just missing nearly 20 percent of last summer's revenue. It's lacking swagger. Summer is the season for mega-budget, chest-thumping, globe-trotting monstrosities — films so big they lure droves of Americans with heavily promoted promises of shock and awe. But this season's blockbuster output has been curiously low on the summer's stock in trade: bigness. Two months into the summer, there haven't been any $300 million grossers at the North American box office.