I did a bit of research on maille-making a couple years ago. See if your library has a copy of Ffoulkes' "The Armourer's Craft". Think it's from 1912, and is somewhat like the armourer's Bealer.
Teh conclusion I came to is this:
- Butted is fine for some situations. Still takes a long time though. Not authentic though; if you can seperate the rings with a pair of needlenose pliers then what chance will there be with a fulll sword swing, even a non-live edge?
- Welding already has been mentioned. You might be able to spot-weld rings, as already mentioned, but forge welding would be a) more authentic more difficult.
- Rivetting/bradding is the way that most maille was constructed 'back in the day.' Still lots of effort. Ffoulkes says that some rings were solid and speculates that they may have been stamped/punched from sheet iron, but IIRC most these days think they are forge welded wire.
Ffoulkes could not, apparently, see the point in solid rings mixed with welded/punched, since a chain is only as strong as its weakest link. However, I think that it was a matter of time saving; you can heat a wire ring to welding heat fairly quickly without the problems associated with heating lots of rings just to weld one, and it was a lot of fiddly work to rivet or brad a ring. With, say, Euro 4-to-1 pattern you would only have to rivet/brad 1 ring for every 5; you make up a bucket of welded rings and link 'em with brads!
Another big problem is finding plain mild steel or iron wire. Mind you, drawing wire down by hand would be good practise
As far as jigs, look up coiling mandrels on maill-making sites. Save you a lot of time!