I heard about a week ago it's the calibre trap. USSR 152 mm for UKR pistols are no longer in use in CEE even, and the lefomtover stocks were finite. The 'Atlantic west' could easily stone RF with 155 mm, however the defenders don't have the machienery to shoot those. Apart from the gifted sets which are very scarce given the length of the front line. And dispersed adding another logistic night mare.