I want to know the answer to the following question:
What was difficult to get set right on the new guns?
All the background I'm provided with is that "It remained in service throughout the war but 18-pdr guns were lined down to take the 13-pdr shell with a larger cartridge producing the 13-pr QF 9 cwt and these proved much more satisfactory.". Is that enough to answer the question?
Answer: no