We report results of a four-year survey of 34761 two-station video meteor events complete to a limiting magnitude of +6. The survey goal was to characterize probable iron meteoroids. Using only physical properties of the meteor trajectories including early peaking light curves, short luminous trajectories, and high energies accumulated per area at beginning, we identified 1068 iron meteors. Our iron candidates are most abundant at slow speeds <15 km/s, where they make up ~20% of the mm-sized meteoroid population. They are overwhelmingly on asteroidal orbits, and have particularly low orbital eccentricities and smaller semi-major axes when compared to non-irons between 10-20 km/s. Our iron population appears to be more numerous at fainter magnitudes, comprising 15% of slow (10-15 km/s) meteors with peak brightness of +3 with the fraction rising to 25% at +6 to +7, our survey limit. We also propose a possible technique using R-band colours to more robustly identify fainter iron meteors with very high confidence.