Hi Boom J, a very interesting question - unfortunately I don't have anything with a history of Armstrong's gun manufacturing output so that is a difficult one for me to answer with certainty, but if you post it on the researchpress.co.uk forum I am sure that Bill Curtis will respond. The references I have are more in regard to Armstrong's designs, patterns, manufacture, etc & relate to patterns adopted by the British Gov't - he didn't supply bronze guns to them as far as I am aware. Sir William Armstrong was a leading engineer in many areas other than ordnance & I find it difficult to imagine him casting bronze ordnance, he was seeking a modern solution, bronze had been around for centuries & its limitations were well known. If he wanted to experiment with rifled bronze guns then I believe that he would have rifled existing guns - as indeed was done by others. You could also post this query on the Palmerston Forts Society forum, there is a font of knowledge there. Adrian.