When working up a new chain link, it is a good idea to practice with copper because it is inexpensive and easy to work with. Working up a few short lengths of copper paper clip chain in different sizes to have on hand will give you a better idea what wire gauge and size chain might be best paired with a new jewelry design.
The metal content as well as the temper of the wire used will slightly change the finished length of a link. Therefore, for your personal reference, it is important to keep track of measurements, sizes, gauges, metals, etc., of the chains YOU make on the blank chart. The Paper Clip Chain Chart contains my reference numbers for dead soft copper wire. My measurements are not standard by any means. They are just what I use for my chains. Use the chart as a starting point for your paper clip chains. Adjust the measurements to make chains that will work best with your vision for a piece of jewelry.
Argentium is great because there is no fire scale to deal with and, most of the time, the rings can be fused.
For these chains, an 8mm mandrel was used to make coils with both 16 and 18 gauge wire.
When I start a project requiring jump rings, I make 3" long coils, or whatever length my remaining in a particular gauge wire will make. The shorter coil here is 18 gauge, the longer coil is 16 gauge. There were enough rings in the 18 gauge coil to make three bracelets. The 16 gauge 3" long coil made an 18" necklace and a bracelet.