Decided to turn on Destiny on Saturday, tried Iron Banner and hit rank 5 by Sunday. It finally pushed me over the 300 barrier, and on to 303 light!
A 300 helm pushed me to 300 light, when I hit rank 4 it gave me a blue relic (which I immediately dismissed, but it was level 310) and at rank 5 it gave me a 311 scout rifle which fucking rips and a 310 ghost shell.
Are you guaranteed level 300+ items from Iron Banner stuff, or is that still based on your light level? I played for months at ~299 and the only time I got an item above 300 was from the one time I raided.