Having become a born again collector I was going through a few shells that I hadn't disposed of when I sold my collection and I have 2 18pdr. shrapnel shells, both Somme battlefield recoveries . Having had many in the past and regretfully given away I noticed one which is quite different to the norm. Firstly the cavity for the expelling charge is much larger and approx. 20mm above where the pusher plate would sit there is another tapered constriction in the bore of the shell. The date of 4/1918 is visible and it's a fired projectile. It's also 12 mm shorter than others I have. Any ideas what the usage was.