It does NOT work. I had to have a tool machined. The allen head is too large for the Spartan inserts. It was a huge fiasco. And the weights won't pass through the nock bushing either. I ended up making the tool. Ordering an extra set of nock bushings and when I cut my arrows, I cut the bushings off. BE wouldn't sell me arrows without the bushings already glued in. The other option, if you know what weight you want up front, is to screw them into the inserts and then glue the whole thing in. But I felt like that defeated the purpose as I was working up arrows. Feel free to PM me with any questions. I had a thread on this a few months ago.