Lead Shot Substitute for Loading Speaker Cabinets?

I have just about given up trying to find lead shot to fill my Von Schweikert VR 4 Jr speakers with. Two questions. Does anyone know where to purchase 100 pounds of lead shot? Are there acceptable substitutes for lead shot when filling up speaker cabineets? Sand maybe?

Thanks in advance.
I am using Micro Bearings from Star Sound , which is like steel sand, VERY heavy and Attabits (sp?), small steel shot which is imported by May Audio. Both are not cheap, another thread on this suggested steel blasting shot, which I haven't tried. It should be cheaper.
Go to a gun shop. If you live in denver I have some I will give you.
Silica sand works well. While not as dense as lead, it is non-toxic and more than heavy enough. It can be gotten at any place that sells sand blasting shot. I use it in the stands of my speakers per the manufacturers recommendation. It is also pretty cheap at about $8 for a 50 pound bag.
There's another thread on substitutes

At Larry Staples {original to LSA}house one evening who had worked with Von Schweikert. We removed the shot from his prototype speakers under test. Replaced with direct coupled Audiopoints. Less dark more speed and a much more dynamic stage. He never used fill material again that I know of. Tom
True Tom.
If anyone has the ability to find this--real wool stuffing is remarkable. It may sound strange, but in the old days, Bud Fried, (Irving M. Fried) used real wool in his IMF's and the results were outstanding. Enough so, that in developing the LSA Statements, I substituted real wool for the inexpensive poly material to really great effect.
For those of you who really enjoy a natural sound, try it. Larry
I am in California and found lead shot at gun stores however it was so expensive I decided to try some substitutes. I ended up using Daisy BB's. If I was to do it again, I also would consider using good ol pennies.

The dust from silica sand is toxic (this is not new news).

This said, I've used and preferred it in speakers (over lead shot and shot/sand mixtures).

Used a damp paper breathing mask when working with it and performed the work outdoors.
If you couple the speakers properly then you don't have to fill anything, worry about toxic abuse or the dark slow muddy sound of over damping a circuit or a speaker. Tom
if they sound good to you,don't load with anything. try changing placement and if they don't sound good to you, 'filling' will not cause a revelation....only a heavier speaker that you don't like anyway.
Actually I LOVE these speakers. I am just trying to coax a little more out of them...maybe on the low end...
vary the placement a bit..perhaps a bit closer to the rear walls....sometimes inches will matter.
My wife said much the same thing.LOL.
mine would agree too