These cases are the shorter Mk II version and not earlier Mk I (long) case.  This was the standard case length in the UK for military loads after the change to cordite as the propellant.  These cases are not headstamped and are nominally 0.77″ long and are meant for use with large pistol primers.  They are priced at 50 cases. Shipping weight is 310 g/50 cases.