I've been doing my first byzantine piece - a bracelet with lampwork beads. I've just been trying to get it finished and I'm really annoyed cos I've just run out of rings and only need 4 more to finish it. I have a few left from another project but the gauge is different. I should have bought two packs of 100 rings

Do you not have any wire in the same gauge? For just four rings, it would be easiest to just cut your own - you can use a pair of round nose pliers instead of a mandrel if necessary, just use one of the existing rings as a template.

I don't know the wire gauge as the website never said. I just ordered one packet to see what they were like. I just know I'm going to end up ordering loads more stuff when I get them at it seems a bit silly buying one packet of jump rings for 90p.