sand versus shot in speaker stands

anything but lead, if anything at all.

I found sand impossible to work with. Any moisture in the air made it clump up and difficult to pour. I went with cat litter, which works well, IMO and is very easy to work with. BTW both Skylan and Totem recommend this product, so I'm not alone in this.

Theo,

You are correct. There is a compnay called Atacama that sells a product called ATABITES.

"High density filler designed for mass loading of speaker stands. Delta shaped chips which interlock together creating minimum air gaps."

http://www.atacama-audio.co.uk/atabites.htm

I've never dealt with commercial stands. The set I made many years ago, before I was even aware of hi-end were filled with Sackrete.
Could you still use lead shot if at the same time you mixed in some expanding foam? That'd seal in the lead at the same time as providing additional damping.
Careful of the ratio, so you don't get a geyser of foam.

You could always look for a well drilling supply place and get colorado silica sand of a given size range. You can get aquarium size sand in a sack, and it will not hold moisture and clump.