US gun enthusiasts fearful of new weapon controls and hearing false rumours of government hoarding are buying bullets practically by the bushel.
The demand is making it hard for gun stores to keep shelves stocked and even putting a pinch on some local law enforcement departments.
The run started in November with President Barack Obama's re-election, followed by the shooting in December of children in Newtown, Connecticut.
That massacre led the president to launch an effort to strengthen federal gun controls and several states to tighten laws.
Connecticut became the latest on Thursday. Hours before the law went into effect, hundreds of customers streamed out of Hoffman's Gun Centre in Newington with guns and boxes of ammunition. Similar scenarios are playing out all over the country.