That is definitely something to watch. I don't own a Royale so I can't say, but I thought I heard that, in general, the 400cc bottles were good for 220 or 230bar and the 500's are good for 250bar... But I'm not 100% on that so don't listen to me! LOL! I do know that all of the 500cc bottles that have passed through my hands have been stamped with 250bar on them.... You bring up a good point: Make sure your bottle or cylinder can handle the pressure before you push your luck!
Scott in CO