How Would The LAV-75 Do

The initial M885 APFSDSDU round would have done 6dx19(2) pi++ inc.

That's good for punching DR 798.

Not near enough for the turret front on a T-80BV which is rocking DR 1,500S.  S for 'spaced' or early laminate armors.

The delta six round was supposed to be more potent.  It does 6dx28(2) pi++ inc.

That's good for punching 1,176 DR.  Not enough to penetrate a T-80BV's frontal armor and barely better than the Sheridan's missiles.

This is kind of why the XM274 was abandoned and the M8 Ridgeway was developed.

The 105mm M900A1 round will do 6dx37(2) pi++ and punch 1,554 DR.

Just enough to gain entry into the turret...

Something the LAV-75 (or the Ridgeway, for that matter) never wants to be is caught where a T-80 can hit them back.

The thickest part of the LAV's armor is DR 150L on the turret.  The 6dx33(2) pi++ punches that handily.  It doesn't even need the armor divisor!

The Ridgeway will have one of three DR's.  But even the Stage III armor only gets to 315L on the front of the turret...  Not even as good as the obsolete Leopard 1.

The M551 Sheridan, that the LAV and M8 never replaced doesn't fare any better should someone manage to get some into service.

It's thickest DR is a mere 200 on the hull front and 150 on the turret front.

The 152mm gun doesn't fare a lot better.  The 6dx9(10) cr ex 6dx7(10) cr ex linked 6dx4 cr ex of the conventional HEAT round only punches 1,260 980 spaced DR, so no good against the T-80BV's turret.  The Shillelagh does 6dx10(10) cr ex 6dx8(10) cr ex linked 6dx4 cr exwhich gets through 1,400 1,120 DR of spaced armor.  I still wonder what would have happened if the MGM-151 had been modernized and upgraded.