"Are you talking about this twist snap? It's a great snap, but once the spring in it wears out, it's pretty much toast :( Sounds like that's what's happened with your snap."
Thank you so much for your input and the pictures. Really, everyone has been very helpful and I'm grateful for all the input. My rope looks just like the one on the bolt snap. On the twist snap, I know there has to be a ball baring and as you twist the collar around there is a point where it kind of "snaps" into place. I tried it again yesterday (seemed to work fine once it was warm) and discovered that with a little more effort I could actually twist the collar in either direction, so I'm guessing there is a small spring in there somewhere that keeps it in place (when it works).
So I can easily replace the snap and that's what I will do. I guess I'm more worked up about this whole thing than I would have been if I wasn't trying to get hold of horses running loose. You know how it is, they are galloping around and I'm having visions of them heading down the road, etc. I talked to another horse friend about this whole thing and she said she would have been upset, too. The design on the collar snap is faulty. While I did use one of the lead ropes quite a bit, the other was not used much at all. Besides ground work in the round pen, I used this lead to load my horses onto their trailer and I can just imagine the clip falling open when we were away from home. Thank goodness, it didn't.