Simulate ore load for MTH ore cars

Contact St Charles Model Works ( www.trainloads.com ), they have excellent ore car loads.

Thanks for the reply.  Checked the web site - could not find a reference to iron ore car loads.  I would prefer to use the existing load inserts and up grade them with a toping of iron ore ballast.  My concern is what size ballast would most closely represent iron ore in O scale.  Wondering if anyone has done this and could recommend a product and size to use.  

Plenty of photos on the internet to help determine the appropriate color and size:

Maybe the first question would be, what era are you modeling? Back in the "old days of steam & early diesels" the iron ore was REAL IRON ORE, which was an orange/rust color. Now, in the "modern era", the load is Taconite, which is a very dark gray color, as the photo of the derailed ore car shows.

I am into steam and early diesel and want my loads to simulate real iron ore.  

Then you definitely need to contact St Charles Model Works. Those ore loads (real steam era looking iron ore) may not show on their website, but a good friend of mine has some 50 or 60 MTH DM&IR ore cars, pulled by either an MTH DM&IR Yellowstone or a Sunset/3rd Rail DM&IR 2-10-4, and every car has a St Charles Model Works iron ore load in it. It is a SPECTACULAR looking train, with everything weathered.

Try calling them and ask for Terry. In my opinion, you will not find better looking iron ore or coal loads for O-Scale cars.