Cannister, grape-shot and double-shotting gave more wear to a gun tube than shot with a wooden bottom. The quote that my dear learned colleague quotes come from the translation of De Scheel (1795) which was a reprinting of Du Coudray writings in defence of the Gribeauval System in 1772 when it was aboloshed. It referred to Prussian guns of the chambered form of M1754 that were not used by the Prussians since 1757. The Prussians used the same weight ratio as the Gribeauval during the Napoleonic Wars.
It is interesting that the tests of Berenger prooved that the Gribeauval guns were not as well founded as the Valliere guns. Ah the test was using half the weight of shot rather than the third of the weight of shot. The same trick was carried out to proove that the AnXI guns were not as good as Gribeauval. This is biasing the results.
Also the optimum length of the guns is related to the speed and the quality of the gunpowder as shown by the tests of Armstrong, Interesting the optimum length of the guns reduced with the increased quality of the power and reducing charges. In 1736, John Armstrong concluded that 20 calibres was the ideal length for the 24-pdr whereas tests in 1775 gave the result of 19 calibres and those by Blomefield c1805 gave 15.5 calibres. Therefore the optimum length was not a constant.
Charge weights are a very interesting area with their reduction. The heat, sound and overpressure being a particular problem as shown by the classic failures of the M1838 Monk 32-pdr, Pattern A tested against the Dundas and Blomefield.