Media playback is unsupported on your device Media caption Watch: Gunmaking in the Philippines is proving a lucrative business, both legal and illegal, reports Kate McGeown from Cebu

A shot rings out from a factory on the outskirts of the Philippines' second-biggest city, Cebu.

But this isn't an all-too-frequent drive-by killing or an argument that has become violent.

The sound is from a testing range at Shooters Arms, the country's second-largest gun factory.

Shooters Arms produces about 20,000 pistols and shotguns every year, 85% of which are sold abroad - mainly to the US, Canada, Italy and Thailand.

Operations manager Romel de Leon has big plans - he wants to expand into new markets in Eastern Europe and even South America.

His business has a lot of competitive advantages. He has low labour costs and a highly skilled workforce using a mix of specialised machines and painstaking manual precision to produce high-quality weapons.

He also has a lucrative local market. Filipinos love their guns - even the president is an enthusiast - and the national police say there are 1.2 million registered firearms in the country.

'Proper livelihood'

But Mr De Leon's factory has another positive factor going for it. In the controversial business of gun manufacturing, he can legitimately claim to be making the world safer rather than more dangerous.

Image caption Romel de Leon hired many people from Danao to set up the second-largest gun factory in The Philippines

Many of the people he employs are from the nearby city of Danao, which is well-known for its gunmaking skills, especially since World War II, when the people of Danao made guns for the resistance effort against the Japanese.

Part of the reason Mr De Leon set up his business near Danao was to tap the potential of these gunsmiths, who had been illegally making unregistered and unregulated firearms inside their homes for decades.

"When we established our business, we hired more than 60% of our employees from Danao. By employing these skilled workers, we provide them a proper livelihood by taking them away from doing illegal gun manufacturing," Mr De Leon said proudly.

But just because Mr De Leon has employed some of Danao's gunsmiths, it doesn't mean that the illegal trade has stopped.

'Feed my family'

It is easy to find gunmakers in Danao - just ask almost any local. There is currently a ban on the carrying of firearms in the Philippines, ahead of congressional elections in May, and many of Danao's gunsmiths have moved from the city centre to homes up in the mountains.

But they are still not hard to find, and trade doesn't seem to be adversely affected.

I met one man who was smoothing out the edges of a pistol in a little rickety shack. Children and chickens jostled for space around him.

"I got into this business through my relatives. I didn't have chance to go to school - my parents were too poor," he said. "This way I can feed my family."

Image caption Illegal gunsmiths don't ask buyers what the weapon will be used for

He is hoping to sell his finished pistol for 5,000 pesos ($125; £80).

He said he doesn't ask what the buyer needs the gun for - and neither do they need to provide any official documents, as they would at Shooters Arms.

"I don't know who the people are who buy my weapons. They just come here and pay in cash," he said.

In a country with a communist rebel group, three Islamic rebel groups, not to mention extortion gangs, hired assassins and more than 100 private armies, it's easy to see why business is good.

Future problems

It is also easy to see why the authorities say they are trying to crack down on the practice.

The police estimate there are 600,000 unregistered and therefore illegal guns in circulation. Independent analysts say there are far more.

In recent months, as in the US, the Philippines has started to soul-search after several shooting sprees and incidents in which children have been hit by stray bullets.

There has been a growing clamour for tighter controls - more restrictions on gun ownership, and more aggressive attempts to stop the manufacture of illegal firearms.

Image caption There have been calls for stricter control over gun ownership

But this is a country where having a gun is almost part of the culture. I have been offered one several times, and certainly in the more dangerous areas of the southern island of Mindanao, almost everyone I know has some sort of firearm.

All security guards are armed, and every person manning the door of a shopping mall or hotel has a shotgun.

It is unlikely that any law will pass that would have a serious impact on the gunmakers at Shooters Arms.

And even the illegal gunsmiths of Danao don't seem particularly concerned.

They know too many people. They've been there too long. They've weathered previous attempts to stop their trade.

So they carry on making their firearms in their little workshops, using their skills and ingenuity to earn a livelihood.

But in doing so, they are creating a lot of problems for the rest of the country, and potentially further afield as well.