HPS bulb. Is this normal?

I purchased a used Sunlight Supply 400watt HPS fixture. It turns on fine and everything works. I don't know if the bulb is any good tho. It rattles when i hold it and give it a lil shake. The inside of the bulbs is hitting the glass from inside. It makes a rattle noise. What does that mean? Is it going bad?

Seems broken...
I would replace it as soon as possible, since even if the bulb is working, being in a damaged state can easily reduce the effective output of your light.
For optimal growth/performance, and in lieu of safety, go get a new one!

Good luck!

Yea somethings not right with it, could be something, could be nothing. I'd get a bulb handy just in case.

replace it, you dont know how many hours are on it either(or do you?). as time goes by a bulb will lose its effectiveness and need to be replaced with a new bulb.

Your bulb is fine physically!! The filament in any brand new HPS bulb will rattle inside the bulb. At least the 25 I have bought have. An HPS bulb will lose 20-40% of it's light output over the course of it's 20,000 hour life so you could change it just because.