Hardee hats were the regulation hat for anything on-duty, like the French and British wore shakos, and the Germans wore those silly pikehelmets. They, next to that, had forage caps.
As far as I know, due to volunteers refusing the Hardee on account of being uncomfortable and stiff, they were stopped being handed out early in the war. Either that, or they ran out of them, but I remember reading letters from Volunteers to home, saying they did receive that. Either I read that in Osprey or some book I'll never find again
Personally, I say they look rather spiffing, especially with the side put up with that eagle-stamp.
Zac, that santa hat actually goes perfect with the Grenadier uniform.
Edit: Oh, and Millander, I hope you don't this the wrong way. What you wear and how is your business and that of your re-enactmentgroup, off course!