What’s the difference among cartridges 400/360 Purdey and 400/360 Westley Richards? And also another variant - Fraser, Evans …? These cartridges are interchangeable? I do not cafe for ballistic differences, but it, whether are cartridges usable in different chambers. It is possible use cartridges Purdey in arms from Westley Richards and below? How is it with modern production these cartridges and with their by using? Further information?