Definitely looks like Panicum but I don't know which one. We have listings in the database with photos for comparison: http://garden.org/plants/searc...
~ I'm an old gal who still loves playing in the dirt!
~ Playing in the dirt is my therapy ... and I'm in therapy a lot!
A little research says that Heavy Metal plumes turn orangey in fall, and Northwind turn yellow beige. They certainly are more similar in appearance than they are different. Good luck. Grasses are a challenge to id.
