TOWN 'N COUNTRYFor Mark Serbu, happiness truly is a warm gun. • "I'm a gun nut. I love guns,'' said the 52-year-old businessman, sitting in his office chair and fiddling with his AR-15, a forerunner to the M-16. In another corner is a fully automatic M-16. Also in his collection, standing on end a few feet away, is a 20mm Gatling cannon used in jet fighters. In the back is an M-2 .50-caliber machine gun. • "I've loved them since I can remember. I like messing with them,'' said Serbu, warming to the subject. "All my friends shoot guns. We have a great time with them. To us, they're these really cool machines that have the ability to destroy or kill if you want, but we usually go and shoot (junk) cars with them in machine gun shoots, or we shoot refrigerators, or we go hog hunting, or prairie dogs. I've shot lots of prairie dogs.''Over the past 17 years, he also has built a successful business making guns. Serbu Firearms Inc., which operates out of a bland building near Tampa International Airport, sells a .50-caliber semiautomatic rifle, accurate up to 1,500 yards; a single-shot .50-caliber rifle; a semiautomatic AR-15 ; and the Super Shorty, a mean-looking sawed-off shotgun with a pistol handle and a fold-down forward grip. Soon, Serbu plans to offer a Super Shorty version with a drum magazine that holds 12 shotgun shells.You can't just go to his shop, plunk down $900 and buy a Super Shorty, however, because they are restricted under the National Firearms Act of 1934, along with machine guns and silencers.You could own one if the county's chief law enforcement officer signs off on it, after you are fingerprinted, photographed and undergo a criminal background check. But it's a political hot potato, Serbu said, and it's rare that a sheriff or state attorney would approve it.You can get a Super Shorty another way, however, and that's to have a corporation or trust own the gun, not a person. A lawyer sets up the trust, and the people who want to use the gun become trustees. A trust also assures the smooth transfer of the restricted firearm to heirs. The lawyer's fee is usually $400 to $500.The law does not require any member of the trust to undergo a background check, said Bob J. Howell of Plantation, near Fort Lauderdale, one of the lawyers who pioneered gun trusts in Florida. However, the main representative of the trust, the person who picks up the firearm, is given an automatic check — through the National Instant Criminal Background Check System — by the Florida Department of Law Enforcement. No background check is required of any other member of the trust, however.Gun trusts have more than doubled since 2008 and were expected to top 40,000 in 2013, said Gary Schaible, an industry liaison analyst with ATF. The bureau has proposed a change to not only require that the main representative of a trust get fingerprinted and photographed, but also that the county's chief law enforcement officer approve it. The agency is expected to decide this year whether to go forward with the rule change."Our concern wouldn't be in the numbers,'' said Schaible. "It would be that anyone touching, holding or possessing these firearms be in compliance with the law.''Some states' laws are more strict than others. New York last year passed the SAFE act, which added Serbu's .50-caliber semiautomatic rifle to the list of outlawed "assault'' weapons. (California banned the rifle in 2005.) In response, when a representative of New York City's police SWAT team inquired about buying some of Serbu's semiautomatics, he declined, saying he would not sell police any weapons that their state's private citizens couldn't buy."We're doing this basically to punish them and try to get support for overturning the law, because it's stupid,'' said Serbu, who is ardently, gleefully combative when it comes to gun restrictions.• • •Eight employees stay busy at Serbu Firearms. Stephen McFarland, 34, at a work bench in back, assembles a .50-caliber semiautomatic. Eden Sucher works at the bench behind him, making legs for the bi-pod stand that supports the barrel. She's been at Serbu Firearms for about six months and is still learning. The 24-year-old said she hopes to be proficient at assembling rifles within the next six months."I went shooting for the first time two years ago and instantly fell in love with the mechanics and how they work,'' she said.On the floor nearby, a dozen or so finished rifles are snug in their cases, waiting to be shipped out to eager customers who paid $6,700 each for them. (The single-shot .50-caliber sells for $2,300.) McFarland said it takes 45 minutes to three hours to put one together, depending on whether its various components, such as the trigger parts, have been assembled. The test is in the firing."They're made, really, with so much zero tolerance, if it goes together, it works. If it doesn't go together, it doesn't work,'' McFarland said.Serbu didn't start out to become a gunmaker, although he said he has loved them since he was a little boy. When he was 4, he said, he asked his parents for a gun that shoots bullets. "It was a lever action, like a copy of an old Winchester, and it had these white plastic bullets that you could load in there. It would eject them, but it didn't shoot, damn it."The Washington, D.C., native graduated from the University of South Florida in 1990 with a degree in mechanical engineering and went to work for a company that makes flight simulators. But he grew bored with it after a few years. He had worked with a friend who made guns in his own basement machine shop and decided to go into the business himself.• • •Serbu made his first sawed-off shotgun for a friend in 1998, thinking at the time that it wouldn't be a big seller. But people seem to love it, he said. His website, serbu.com, boasts that more than 1,000 have been sold. It's such an eye-catcher that it has starred in television shows, video games and movies, including Bad Boys II, Crank and The Expendables. "It's definitely cool. I never would have thought years ago, 'Gosh, I'm going to make guns and they're going to be in the movies someday,' '' he said.Serbu said the Bureau of Alcohol, Tobacco, Firearms and Explosives has put traces, sometimes urgent traces, on the Super Shorty at the request of law enforcement agencies, and from that he assumes that the gun has been used in homicides. On one hand, he said, he feels bad."But if some dirtbag got blown away, then I feel great. So you just never know,'' he said.Serbu sells to police departments around the country and to foreign governments; he sold some Super Shorty guns to the king of Jordan. But Serbu figures most individuals who buy his guns like them because they're cool looking, fun to show off and fun to fire."I've got a $12,000 thermal scope sitting in that military backpack, and I'm going to put it on top of this sucker (the AR-15), and I'm going to go shoot some hogs with it,'' he said."There's no need for that. But, you know, it's fun, and I want to do it, and it's going to be great.''John Martin contributed to this report. Philip Morgan can be reached at [email protected] or (813) 226-3435.