I'm shooting using a Nikon F5 and bulk-loaded film in plastic canisters. I'm getting some weird stripes on each roll of film lately. I'm attaching a couple of sample images, and I'm hoping someone might be able to give me an idea of what's causing the stripes.
An image that has the stripes (I'm talking about the 2 dark lines near the center of the image)
Detail of the stripes