Originally Posted by
henra
Rifling doesn't work well for high speed projectiles. Max projectile speed (and thus kinetic ernergy) with rifled barrels is limited due to increased friction. It is good for accuracy of slower rounds, though. Re-active armor generally works better against HE than against APFSDS. Thus, APFSDS have become the preferred choice for tank2tank battle. That's why in general the smoothbore guns are preferred in modern tank design.
And yet the current longest confirmed tank vs tank kill is 5,100m, by a Challenger 1 crew using an
APFSDS from a rifled barrel.