[quote:3k8y5269]it only happens on my iphone. On my desktop, it didn't happen a single time and i checked that a lot of times
There is a correlation between framerate, object size and object speed that explains when tunneling can or cannot happen. What I meant when I said the framerate was "irrelevant" is that 30 or 60fps, or even 120fps, doesn't guarantee consistent collision detection ; if you had smaller or faster moving objects at 60fps, you could see the same issue.
Commercial games use solutions that work decently in all situations ; for example a bullet in a first person shooter, a small and fast moving object, is never actually a bullet from a physics representation point of view, it's a line, and physics raychecks are used to compute collisions so that bullets don't through thin walls.
As for doing this with C2... No idea, honestly. But the problem is well-known.
'Hope that helps a bit !