Maybe the 30 grain Eley Magnum? It’s hard to find, but still available over-seas and on ebay occassionally. At $30 a tin, I’d stick to the Eun Jins or Kodiaks. I’ve seen something about “air bullets” on a post here, but don’t know if the were .22 or a bit larger.
Daystate makes a 40gr pellet but I think they can only be used in the 80fpe air ranger.
Like TT said, its chambered for .223 never tried them, but know for certain that .22 lr rounds fit to tight in a .22 airgun barrel. The Eley Magnums are a tight fit also, but the heaviest commercialy available 300 for $30 kinda high priced. Airguns of arizona has them listed. 30g pile drivers 100 per tin are listed http://www.airgunsofarizona.com/ $13.95,I have heard mixed replies about those as well, like save your money to they work all right but are tight to fit. To much to drop for plinking purposes. The best bet is Eun Jins 28.4g. I read every once and awhile about limited batches of .22 airgun bullets being made 30+g range, but nothing commercially available.