According to Task & Purpose, "Russia is hammering Ukraine with up to 60,000 artillery shells and rockets every day".
The Russians are using indiscriminate and overwhelming artillery strikes to grind Ukrainian defenders down, underscoring how the Russian military’s approach to firepower prizes volume over accuracy.
The war in eastern Ukraine has been described as an artillery duel, and the Russian military has superior numbers of cannons and rocket artillery systems. Right now, the Russians are currently blasting the Donets Basin – known as the Donbas – with up to 60,000 artillery shells and rockets per day, one unnamed senior advisor to the Ukrainian military told The New York Times recently.
. . .
It appears the Russians are currently preserving their precision-guided munitions, said Glen Howard, a Russia expert and president of the conservative Jamestown Foundation think tank in Washington, D.C.
In fact, experts are debating exactly how many precision-guided weapons the Russians have left because the Russian military has started using older Kh-22 cruise missiles, which first entered service in the 1960s, Howard told Task & Purpose.
There's more at the link.
The figure of 60,000 may be an exaggeration; certainly, it wasn't the case at the start of the war, when Russia deployed more smart weapons - albeit in a very non-smart way! - and had fewer conventional artillery units on the front lines. However, as Russia was driven back in the north and shifted its operational focus to the Donbas and Luhansk regions and surrounding areas, it reverted its operational doctrine to that used from the Second World War, through Afghanistan, to the battles in Chechnya in the late 1990's - artillery barrages with "dumb", unguided shells, designed to obliterate opposition in an area rather than target defenses with pinpoint accuracy.
To do that requires a very deep reserve of artillery ammunition. Russia has that. It produced vast quantities of artillery shells since World War II, and continued to do so every year, probably on the basis that conventional artillery rounds are relatively cheap and easy to produce in comparison to "smart" weapons. Once a factory is producing (say) a hundred thousand artillery shells every year, it's easy to just let it go on doing so, keeping people employed and adding to the stockpile. Provided trains and trucks can move those stockpiles to where they're needed (along with rations, fuel and everything else an army needs), they'll be just as deadly as a "smart" weapon if they go off close enough to a target.
What's more, the artillery pieces and self-propelled cannon that fire those shells are still stored in their tens of thousands. In combat in Angola in the 1970's and 1980's, we faced obsolete and cast-off Russian cannon by the hundreds. We captured so many of them that we fully equipped UNITA with them, plus more ammunition than they could shoot, all courtesy of the Angolan army. The ammunition was sometimes a nightmare to handle. Some dated back to WW2, and didn't take kindly to being left out in stacks in the unrelenting heat of the African sun. I recall an artillery officer bringing forward some trucks to take away captured ammo. He took one look at the dates on it, gingerly felt a shell to see how hot it was, hurriedly snatched his hand away before it could be burned, and said (in so many words) "Forget it! This stuff's so old and decrepit, it's too dangerous for the Angolans to shoot, never mind us!" We placed demolition charges on it and headed out. A short while later, a thunderous blast and a roiling, rising cloud of smoke behind us showed that the threat had been removed.
The same problem affected rockets, land mines and other munitions. I've handled a SA-7 shoulder-fired anti-aircraft missile that was more than 20 years old. Its battery pack had run down heaven knows how long ago, and the person carrying it hadn't bothered to replace it, so it wouldn't have worked even if he'd pulled the trigger. We had fresh batteries, but again, an ordnance specialist looked at it, went pale, and muttered something about "not wanting that old warhead anywhere near his head" (the rocket tube was shouldered to fire it).
I guess Russia is drawing down all those decades-old stockpiles of artillery shells, and using them up in Ukraine. They're freely available, cheap, and don't cost money to replace, because many of the old artillery pieces shooting them are no longer front-line equipment. The defense budget can thus be reserved for (much more expensive) "smart" weapons.
However, the artillery tactics used by the Soviets in World War II will still produce results in this day and age. A pulverized defensive line is still pulverized, no matter what caused the damage. Josef Stalin called artillery "the god of war". Here's archival Soviet propaganda footage of their artillery during World War 2.
Whilst current artillery barrages in Ukraine probably aren't of that intensity, it's still a mighty unpleasant experience to be on the receiving end.
I wonder how extensive US artillery ammo stockpiles are right now? If we go into action in Europe, how long will they last? After sending so many artillery shells to Ukraine, that's not a bad question to ask, no matter how politically incorrect it may be. I rather suspect Russia has a lot more in its stockpiles than we do . . .