Which stone for backfill behind sleepers

[renishawphil]

I have quite a lot of fill to out behind a retaining wall made of sleepers below the soil layer.

I am loathed to use recycled hard core and am thinking road stone. It's going to be in the region of 10 tonnes of material.
Would road stone be best ? Or should I look at something else?
Also am I right to keep away from recycled hard core

 

[r896neo]

What will the finished surface be on the higher area behind the wall?

If its lawn then stony or sandy sub soil will do well. Then finish the top 200mm with topsoil and a little coarse sand.

Or is it to be a driveway or pathway?