Ukraine

It has typically been 60/day for months. The last few days has been around 30/day, so we might just be catching up on some destroyed but not counted before. Or Ukraine might have got a bunch.

Russia has a lot of old Soviet gear in storage. They can refurbish those at current rates for another year or more. Of course they are getting into WWII designs (manufactures in the 1950s). So while I cheer every artillery destroyed, it realistically doesn't make much a difference for the near future, though in 6 months or a year Russia will run out of those and then they will have problems.

Ukraine's recent hit of an ammunition storage likely destroyed several months of artillery shells though and if so that will make a large difference.