I worked at a plant for 20 years, fresh out of high school.  When I started, 20% was insane. Now they're running over 50% in their 301 base material. This may be great for cost savings at a glance, but coming from a plant operator, we hated it. It was a bitch to get up to temperature, the bag house would be too cold and potentially mud up, RAP chutes would plug more often, etc etc. And we kept out RAP indoors directly after milling to keep them dry too... so all those negatives lead to slower production and not being able to keep up with demand... so... are we really saving?