I'm currently using AA Diabolo Fields (4.52) in my HFT500. The grouping is OK at 25 yards, best group so far is 7mm outside edge to outside edge. Usual is 5p piece size or a bit better. JSB Exacts were disappointing, opening the group up to 20mm with far too many flyers.
I will pick up some QYS domed (4.50) and Heavy FT (in 4.49) later this week. This is all I could get from my drive-by RFD. Does the 0.01mm nominal diameter mean anything? I've tried measuring other pellets in the past and the stated diameter is, frankly, a bit of a joke. Are QYS as good as folks seem to say?

What are other HFT500 owners loving? (yes, all barrels are different). I like to pick up pellets in person as I've had some bad experiences with damaged couriered ammo in the past. Granted, this will seriously limit my choice.
Thanks in advance.