LEWISTON – For firearms dealers, there are two pressing questions: Where has all the ammunition gone, and why?

A recent run on ammo has caused supplies to run short. Some say it might be due to pending legislation that will require ammunition to be stamped for identification. Others say that like many things in the world of weaponry, the shortage defies explanation.

“There are reasons for it, but no one seems to know what those reasons are,” said Marcel Morin, owner of Pine Tree Trading in Lewiston. “People are buying ammunition by the ton.”

At a recent gun show in Lewiston, $15,000 worth sold in one day. Every dealer at the show sold out. Ammunition for common guns like the .380, .45 and 38 Specials are being gobbled up so fast dealers are having trouble stocking their shelves.

“I can’t even get it,” said Jamie Pelletier at Reid’s Guns & Cigars in Auburn. “It’s everything. Pistol ammo is real hard to get. So is some of the rifle ammo.”

Gun dealers compare the problem to the stock market. Changes within the nation’s leadership might spur a spike in sales. Rumors about new laws might have the same effect, even if they’re not true.

Gun dealers say there are fears that President Barack Obama might eventually ban some guns or create enormous taxes on ammunition.

There is also talk among gun owners of micro-stamping, an idea that would require bullets to be encoded with information so police and others could determine where the ammunition came from.

A bill proposed last year with that kind of ammo stamping went nowhere. But some, according to Pelletier, still fear that such a law could be in the works and that it would make the purchase of ammunition more difficult and costly.

“Everybody is worried about that micro-stamping of the ammo,” he said. “People are just concerned. They’re stocking up.”

Whatever the reason, ammunition is selling faster than guns around the country. No one knows how long the run on ammo will last. At Howell’s Gun Shop in Gray, a dealer said ammunition for the .223 rifle was in particularly hot demand, followed by ammo for .380-caliber pistols.

“It’s awful,” said Morin, at Pine Tree Trading. “I went to order ammo this morning and there was nothing around.”

So far, police departments have not encountered a reason to ration ammunition used for range shooting or for rounds carried by officers. Part of the reason for that, according to Lewiston Deputy Chief Michael Bussiere, is that the departments tend to get their supply of ammunition well in advance.

“We make sure we have enough for the ranges and the duty ammo,” Bussiere said. “It hasn’t really affected us.”

Likewise, in Auburn, police administrators said they had heard about shortages, but they generally have not affected the ammunition the officers need.

“Our .45-caliber handgun inventory is where it needs to be,” said Auburn Deputy Chief Jason Moen. “We are not facing any shortages.”