NEW YORK (CNNMoney) The feverish demand for military-style rifles and high-capacity ammunition magazines is outstripping supply, ahead of legislative efforts to ban them in the wake of mass shootings.Online retailers are running out of semiautomatic rifles — known variously as assault weapons, tactical rifles or modern sporting rifles — and magazines that can hold more than 10 rounds.Brick-and-mortar gun shops are also working furiously to meet demand. Semiautomatic rifles, which fire one round for every pull of the trigger, and high-capacity magazines are flying off the shelves.Pratte said that he sells AR-15s as soon as they arrive at his store, before he even has the time to display them on the wall. Handguns are also hot commodities, especially from popular makers such as Smith & Wesson (SWHC), he said.He said that prices are soaring, and not just for guns. High-capacity magazines, particularly the popular 30-round magazines, are going for $100 apiece on Gunbroker.com, a bidding site like Ebay (EBAY, Fortune 500). He said they used to sell for $15.