The Daily Mail has published a few interesting photos of guns used by the Moro Islamic Liberation Front (MILF … who did you think the title referred to?) in the Philippines. One of the guns, an M16, caught the eye of a TFB reader. The barrel is a little strange, it has round bumps along the length of it. I can’t work out if it is decoration, some sort of primitive heatsink or a feature of the steel pipe used to make the barrel in the first place. What do you think?

Many thanks to Tom for the tip.