There are specific bullets designed for the 30-30. The 308, 30-06, 300 mag, 300WSM, etc can use the same projectiles. The 30-30 and the rest of the thirties appear to have the same diameter of .308 but you do not want a pointed bullet in a 30-30 (Leverevolution is an exception). Traditional 30-30 projectiles have a flat point so as not to set off the primer of the round in front of it. Most projectiles designed for 30-30 will be labeled as such.
As far as bulk ammo... I have no idea where to find bulk 30-30. I would look at Cabelas, BassPro, Ammoman, Ammotogo....just go to Google and run a search for "bulk 30-30 ammo" It should get you started. Hope all this helps you out.