I found this one at a gun show several years ago. It was just prior to Privi Partisan (PPU) starting up production of the ammo again. I paid about $60 for an old box of Peters ammo just to have something to shoot and some brass for reloading. The hard components to find are the Hornady #2210 40 grain, .222" bullets that Jetman22 shows above. I think Hornady stopped manufacture of them several years ago in order to keep up with the demand for bullets used in all of the AR15 type rifles. You can sometimes find Sierra .223" 45 grain Hornet bullets that are supposed to shoot OK.
I have not chronographed the PPU ammo but I suspect it is loaded to a little lower velocity than the original ammo, and will likely be easier on the forcing cone.
I also have a Ruger Hawkeye in .256 Magnum. It shoots a 60 grain .25 caliber bullet from a necked down .357 case. Another problem child. I like the oddballs I guess.