The Russian gunnery was not as accurate as that of other nations which is one reason that they used more guns than anyone else, substituting mass for accuracy.
do you have any sources for that--that the Russians consciously substituted Mass for accuracy? Alexander Mikaberidze's book on Borodino gives only a few examples of the Russians using twelve guns of the same battery together, but several of half-batteries being moved and deployed.
As for the offensive use of artillery, it would seem that the Russians would have to be on the offensive to use them offensively. Even so, Alexander's K's books on Russian Tactics provides some incidents that might fit.