These are Nanos Metalfigs which comes as nasty enamel pre-paints. Other than one very expensive set of resin figures, these appear to be the only gaming-scale Harry Potter figures that have a good range of characters.
The figures are a bit tall (32-35mm?) and the scale varies between figures (so everyone is about the same height). I stripped the enamel paint off using some acetone and then repainted. Mostly this worked out. The difficult part was Harry's glasses (looks like he shares an optometrist with Himmler, but whatever).
There is quite a range of figures from different parts of the series. I started with Year 1 kids and Snape. I have some Year 7 kids and Dumbledore underway. I'm also short about half of the 30 poses and have been watching eBay.
Up next: Probably more Harry Potter and maybe even some gaming.