Way in which this is a sound piece of weaponry? (8)
I believe the answer is:
howitzer
'weaponry?' is the definition.
(howitzer is a kind of weaponry)
'way in which this is a sound piece' is the wordplay.
'way in which' becomes 'how' (how something is done).
'this is a sound piece' becomes 'itzer' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'how'+'itzer'='HOWITZER'
'of' is the link.
(Other definitions for howitzer that I've seen before include "Artillery weapon" , "Shell-firing cannon" , "Short-range cannon" , "Short-barrel cannon" , "Short, heavy gun fired at an angle" .)