Reuters: vertice NATO per concordare standardizzazione proiettili da 155 mm

I love the comment in the article that due to differences in the 155mm standard used by NATO nations, some shells might be 10s of meters out if the operators don’t adjust settings

Small differences in weight and propellant charges can be significant when firing 20 Km and trying to hit a target a few meters across. No real need to have a non standard shell except maybe for some specialty shells like the GPS guided ones or the artillery laid mines.