577 Deep Seat ball round


I have had a couple of these interesting British rounds for about 10 years waiting for some info to appear in print about them ,so far nothing that I have seen the headstamp is, KYNOCH .577 the lead copper tube bullet is seated just above the case mouth and there are 2 dot case crimps 1/2 inch from neck to secure bullet, I am sure its a genuine Kynoch factory round , what I would like to know is the reason they were made ,why a deep seat bullet was it a target round or a light load for the ladies to shoot or some other reason ,any one know ? thanks Randy


Any chance of a picture?