Tricky.
By its small size, I would say it seems to be a "Barbarous Radiate" i.e. an ancient imitation of a late third century AE Antoninianus, typically imitating one of Tetricus I or Claudius II.
Below is an example I had, imitating Tetricus I, found in Norfolk. It was chunky as well

By its small size, I would say it seems to be a "Barbarous Radiate" i.e. an ancient imitation of a late third century AE Antoninianus, typically imitating one of Tetricus I or Claudius II.
Below is an example I had, imitating Tetricus I, found in Norfolk. It was chunky as well























