In any case, I finally made a good one with 14 gauge brass.
The red-coated copper fibula was way too fine a gauge, but I just wanted to practice the moves. Trying to shape it by hammering destroyed the piece utterly. (I won’t lie: that was kind of fun.) The next one, 16 gauge copper, was going well, until I tried hammering it with a chasing hammer. Yeah, a hammer with a flat surface is not good for that; you need something a little bit rounded or you’re going to get bite marks. Even a plain old household hammer is good, if the surface isn’t badly marred. Attempt #3, 16 gauge brass, was going swell, except I measured wrong and couldn’t complete the pin because it came up too short! I’m glad that happened though, because it spurred me to find some 14 gauge wire (hard to find in my local craft shops) in the classroom. Now THAT was just perfect. Hard to manipulate, but clearly I’d had practice. Plus, it was easy to make a consistent, well-curved spiral. Now all I have to do is sand and refine the pin part a little bit . . . and be careful not to make dents in the double loop area next time.