Try Smith and Son Ballast, you'll find they have an ad in Model Railroader. Scenic Express sells some of their stuff, but only some and they charge a little more. You can deal directly with Smith and Son Ballast and get it in quantity. They sell it in small bags or inbilk by the pound. You can also get small bags of the various grades/sizes to see what it looks like in person for a small charge per bag.
We use their unit train coal for the live loads we run and their ballast and cinders too.
They're really great folks to deal with and like their ballast, it is real coal that they crush. I think they have a little rock crushing rig in their garage.
This is their address: Smith and Sons Ballast 13630 Gar Highway Chardon, OH 44024
Buy a bag of real coal and beat it with a hammer was done back in the 40's. A really good substitute and is under $5.00 for a 50 pound bag is a grit blast media called Black Beauty. It is an aluminum oxide material (read does not conduct electricity) used for sand blasting and is very common at sand blast supply houses. My one bag has been sprinkled on my driveway after yearly tarring twice and filled over fifty hoppers. I still have ten pounds left.
Make your own. Small bag of coal from woodland scenics and some sheet styrene and some glue. Maybe about 1/4th the price of ready made. I filled some tenders with real coal crushed with a hammer in a canvas bag. You cant get more realistic than that.
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!