{HEAD ~ a sabot} having a front end face with an annular groove therein, a smooth tapered annular zone extending rearwardly of said front end face and a circular groove to {TAIL ~ the rear} of said annular zone 
{ HEAD ~ a sabot } having a front end face with an annular groove therein , a smooth tapered annular zone extending rearwardly of said front end face and a circular groove to { TAIL ~ the rear } of said annular zone
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH