For the past six years, rebel units have swept through the towns, looting, killing and raping, often followed by an army which has become a virtual rabble - unpaid, unfed and no longer owing an allegiance to anyone but themselves.
Children brought into the conflict by kidnapping, the death of their families, or the thrill of adventure have often seen the semi-automatic as the way to riches and power.
Mohammed Jajva, a cocky 19-year-old, is happy to tell his stories of ambushes and eyeball-to-eyeball battles with the Revolutionary United Front. "I joined the army at 16 because the rebels killed my five brothers. I operated the AK-58. It was my first time with guns, but when I had the chance to kill a rebel I did. I have killed about 20. After the first time I had nightmares, but now I am used to it."
The charity Concern Universal has encouraged the Sierra Leone government to demobilise boy soldiers and has set up homes and camps to rehabilitate them. Many have dreadful injuries and psychological scars from the horrors they have witnessed.
Amadu Mansaray, an 11-year-old, has lost his childish innocence. His face is a mask and his eyes ice cold. He recites the story of his time in the army - and the scores he killed - in a clipped monotone.
At the same camp where he is being treated, about 15 girls are undergoing their own programme. Some fought alongside the young men, but most were kidnapped and forced to carry ammunition, water and food for their captors. Many were miserably treated and repeatedly raped.
The camps have a hard task, and last month's coup in Freetown threatens a new wave of violence through the country. Alo Donnelly, chief executive of Concern Universal, said: "At the moment we don't even know if we have a programme any more. Freetown has all but ceased to exist as a town. Nobody can get money or food and we are unable to pay our staff in the camps or feed the children.
"For many of these children, who have only just given up their guns, it will be all but impossible to resist the return."