Welcome to the 6mm ARC forums charliebrown. I'm an old shooter myself that still enjoys making guns go bang. I agree that the 6mm ARC is probably the best cartridge for the AR15 yet devised. I ordered a AR barrel back in September. I also ordered ammo for it at the same time so when my barrel finally arrives I'll have something to shoot. I have the ammo but I'm still waiting for that barrel. I recently ordered a bolt gun upper that fits on an AR lower. I'm wondering which one I get first. Getting anything gun related these days is an exercise in frustration... 
The trick is growing up without growing old. -- Casey Stengal