I'm not 100% certain but I think Hull Cartridge Company http://www.hullcartridge.co.uk/ may load for Holland & Holland. I have just looked through their website for a comparable cartridge but can't find one although I bought a case of their 'Trainer' brand cartridges not all that long ago which seem to be along similar lines although not now listed for some reason. They are 15/16th. ounce No.7 shot but with paper cases. Nice to use and I would suspect are the same. Maybe if Holland's won't supply the info then Hull might. Lagopus.....