The Sharps cases and chambering reamers might be more easily obtained? The larger rim diameter of the Express brass might be found to be attractive as well.

A .45 3 1/4", for instance, can be 'held back for any length between that and the 2.4". The shortest case might need a polishing out of the head area - or not, depending on the diameter of the reamer at the .85" distance from the headstamp as that would be the head 'region' for the 2.4".