sabotloader,
I'm looking forward to hear how well you like this spin jag. I've seen them advertised, but I've never held one in my hands.It is a little pricey$$
I've always drilled and tapped my jags tofit a 10-32 set screw. The set screw is stronger than the brass and I leave the jag loose on my range rod. The jag follows the rifling really well. I've never had to replace one of these set ups and I clean for the most part between each shot, so it gets a work out.
I must say that the spin jag does look high tech in comparison.