From a small Airgun shop. The cardboard box looks very retro and the pellets therein look well and truly oxidised. I wonder how old that box is; maybe the style was not retro when the pellets were actually packed. I reckon that box is very old. New Old Stock maybe.
Anyway, they were cheap and they fit the Webley Hurricane "22-5.6 CAL" barrel well - best power yet: 3.0 fpe.
.22 inch is 5.588 millimetres.
I don't suppose anyone makes true .22 pellets now.