[But that was for an army of millions. The Russian forces in the Ukraine are more like 150K.
A Battalion Tactical Group has six howitzers. They have about 40 BTGs that were actively engaged in the Donbas - about 240 tubes. Every one would have to fire a couple of hundred rounds per day for them to fire 50,000 in a day. The barrels would need to be replaced about every other week.
I just doubt that they are are sustaining that rate of fire, for maintenance, as well as supply reasons, as well as personnel reasons. That would be humping ten tons of shells every day, for every gun crew.
I could see them possibly peaking for a particular operation, but not coordinating hundreds of crews doing that every day.]
I believe the ten to one ratio of Artillery, even maybe 20-1, at a given time and place. Offense gets to pick the time and place to concentrate, defense has to be everywhere.
It seems that that phase of the war (Russians able to just consistently blast their way through with tube Artillery) may be over, with the new ability of the Ukrainians to disrupt Russian Artillery supply with deep strikes. We will see if Russian forces can counter, or adapt to, that new situation.
I have not heard much about the counter-battery battle, to know if that has shifted as well. The relatively sudden lessening of Russian Artillery fire might also have been precipitated by their Artillery batteries getting hit with newly effective counter battery fire, and them pulling in their horns while they analyze the new threat. That is just a possibility I am considering - I have not seen indications of that (although I have been anticipating some such capability would be forthcoming, as the Ukrainians were being so effectively pummeled by Russian Arty).