I made up many of these bars made of Tungsten , and steel filled with lead shot . It helped with chatter . We were developing a munition and the original design was damn near unobtainable . I suggested to thread the Tungsten penetrators and the Sabots for an exact fit . They bought it , and we did it . Once they saw how easy it was to set the distance they needed where the 2 met , it was a nice production job for me on the CNC Makino . I did get a very small amount of money from them for the suggestion but not much .
I used Tungsten bars for the job with no issues and the Sabots were approx. 6" long .
Someone on here bought some of unfinished penetrators and machined them into darts . I guess it worked out .