I own a Lyman 2500 Pro Mag and use it maybe once/twice a year. There always seems to be a minor catastrophe every time I use it. Media leaking out or what have you. I typically set it up on a carpet scrap, then cover it with a big plastic bin to keep the noise down. I just ran it for about 24 hours and there was a lot of media dust that had leaked out of someplace, IMO it was likely the cover to bowl interface. Not the actual media, but a very fine dust.

>>> QUESTION: Is there supposed to be a gasket between the cover and the bowl? I thought even my cheapo Harbor Freight tumbler had a gasket in that position, but my Lyman does not? Is this correct?

https://www.harborfreight.com/5-lb-metal-vibrator-tumbler-67617.html

This one does, and was my last tumbler, but based on your comment, I guess it's not a thing. I do need to figure out where all that dust came from though.

Well, I like making stuff, but I agree that it may not be worth it.

The plastic bin I covered it with seems to contain the mess, so I'll just continue doing that.