I would suspect the Holland & Holland cartridges have been loaded for them; probably by Hull Cartridges Co. Paper cases are just a little more expensive than plastic. Some shoots like you to pick up your empties at the end of the drive or at least live them in a small pile at your stand. One shoot I have been to have the Keeper's young son go round each stand or peg with a bucket at the end of the drive. He does well for tips. Good luck. Lagopus.....