Whatever the reason, four of the top 10 states in the nation in licensed gun dealers per capita are located in the West: Montana, Wyoming, Oregon and Idaho, the latter having 664 licensed dealers, including Red's. Most of the rest of the Western states are above the national average in terms of gun-dealing. And in the last 15 years, most Western states have made it easier for people to get a state permit to carry concealed weapons. (View a map of gun groups, gun dealers, and gun personalities in the western states. 160kb .pdf)

The West isn't entirely free of gun regulation; in primary and secondary schools and on college campuses, for example, guns are generally banned. Still, there's a lot of wrangling over exactly where to draw the lines, making gun laws an inconsistent mess, each state adding its own layer to the federal gun-control system.

Machine guns, for example, are highly regulated. Sort of. If you're an average citizen, by federal law you can buy a machine gun from a specially licensed dealer, if you submit fingerprints for a comprehensive check for any past criminal activity, and if you can afford to pay a $200 tax on each machine gun. The machine guns themselves must be at least 21 years old (no kidding). Your state may impose more restrictions, or it may not. Just in case the cattle dung ever hits the fan, Western civilians have acquired the special permits to own more than 50,000 machine guns, according to a 2000 federal report.

For other kinds of guns, millions of sellers and buyers who do not have formal gun businesses — they use classified ads, flea markets, word-of-mouth, and gun shows — remain nearly unregulated, except in the few states that have applicable laws. That helps explain how 17-year-old Sulejman Talovic was able to go on his shooting spree in a Salt Lake City mall on Feb. 12 (six people dead, including Talovic, and four wounded). Talovic bought a pistol from a couple of guys he met at a fast-food restaurant, authorities say.

Gun shops — theoretically the primary firearms marketplace — must be federally licensed. The clerks are required to do basic, instant background checks on all their customers, by Internet or toll-free call, tapping into a federal database that supposedly reveals who is too much of a criminal, or too mentally ill, to own a gun.

But there are big gaps in the database. States are supposed to tell the feds about court actions that record their residents' mental illnesses, for example, but states are often negligent or late in passing on the data. That helps explain an April 16 shooting spree back East: Seung-Hui Cho was able to buy his guns from a Virginia shop, even though he'd been court-ordered into psychiatric outpatient treatment two years earlier. The Virginia system had not reported his illness to the federal database, and that recordkeeping failure helped enable Cho to shoot and kill 32 people before he shot himself at Virginia Tech University.

Also by federal law, gun-shop clerks must fill out detailed federal forms, and they must keep the resulting paperwork on who buys what guns for 20 years after each sale. But, in a glaring act of hypocrisy, the federal government keeps its copies of the sales records for only one day and then destroys them, because the gun-rights movement, citing concern for gun owners' privacy, successfully pressured Congress and the Bush administration to require the shredding. Some state governments see this intentional federal ignorance as negligence, and they collect the records within their borders.

Anyway, the federal paperwork is where Red's Trading Post got into trouble, mostly. The feds say the clerks at Red's didn't properly fill out forms on several hundred sales, out of many thousands of total transactions. The ATF made its case by dispatching agents to inspect Red's records in 2000, again in 2001, again in 2005, and then at least four times this year.

Paperwork imperfection can indicate larger problems. Last year, the feds yanked the license of Northern California's biggest gun shop, Trader Sports in San Leandro, charging that the owner could not account for 1,723 guns. Gun-control groups said hundreds of those missing guns could be linked to street crimes.

But only a few gun shops have problems that big. At Red's, the ATF's inspection in 2000 determined that 25 guns were missing. Horsley says he was getting his record-keeping up to speed after his relatives had run the shop on a smaller scale. When the ATF discovered the guns were missing, he tracked down about half of them; the rest may have been stolen, he says. Since 2000, he adds, no guns are missing. In their voluminous court filings against Red's, the feds do not report any more missing guns, nor do they link any of the missing guns from seven years ago to any street crimes. The offenses at Red's mostly have to do with what could seem like technicalities: recording incomplete addresses of customers, not keeping 20 years of sales records in correct order, failing to check a few customers' IDs properly.

Horsley calls them "minor errors" and contends that more than 95 percent of his paperwork has passed muster. He's mounted a furious resistance to what he sees as harassment. When an ATF regional boss in Seattle decided to yank his license in 2006, Horsley appealed the decision through an ATF administrative hearing, which he lost. Then he filed a lawsuit in federal court in Boise, challenging the decision. On March 31 this year, Judge Edward Lodge issued a temporary injunction, allowing Red's to stay in business until he weighs additional evidence. The judge, an Idaho native, said that it appeared the ATF had exaggerated its case against Red's, and that allowing Red's to sell guns for a while longer "would not place the public's safety in jeopardy."

Since that ruling, the ATF has inspected Red's four times in rapid succession, finding additional violations. Everyone is waiting for the judge to make a final ruling.

Horsley has presented his side of the dispute directly to the public, in interviews in the Twin Falls daily newspaper. He's run TV ads about his battle and posted them on Red's Web site; supporters have spread them onto the global YouTube site. He's also posted an online petition, which, apparently, more than 2,000 people across the nation have signed. He's done interviews on national radio shows sympathetic to his plight.

The feds have been characteristically tight-lipped about their enforcement actions.