[jester]

I would also add that cleaning would also play a role. Firing a corrossive ammo then not cleaning it would add to barrel wear as the corrosive salts would have more time to eat away the metal. As well as the intensity of the fire. Firing ALOT without letting the barrel cool would cause greater wear, so LOTS of fire missions back to back, vice one fire mission then nothing then another here and there even though the same number of rounds would be fired in a month, the more rounds fired at one go would cause greater wear.

And as was said the type of rounds, some rounds are lower velocity than others, an example, a 203 firing an illum round vice an HE round, same with the artillery, an illum or even a canister well they are lighter rounds with less frction than a traditional HE thus less wear.

And again maintenance would play a part too. A gun left on the docks suffering the effects of salt air vice one in a dry desert, well one would suffer more enviromental effects than the other. But, then again the effects of the scouring action of desert or even lots of fine dirt and grit in the air and coating equipment acting as emery powder would also account for greater wear.

There are so many factors that do affect a weapons wear.