No, the .50 SLAP does not work on IFV's like the Bradley, Warrior except possibly the rear armour, don't know if they have tested against the rear armour. I know the Strf90(CV90) has been tested against various .50 SLAP and API rounds, especially against the rear armour, and the rounds have failed to penetrate. I'm also skeptic about it penetrating the BMP-3. Remember, the original BMP design is from the 50's and 60's, just like the M113, while the BMP-3 is far newer.
the bradley uses aluminum for armor, not sure how thick, but i would have thought the SLAP coulda penetrated it... i dont know what the BMP-3 has for armor, my guess is it would be comperable to the bradley
if its not good for armor, its overkill for infantry, what good is it?
And, how about shooting through the armour of a HUMVEE at 1500m? Or through the armoured glass of a helicopter? Or trash the engine of a truck? Or destruction of a machine gun nest? Shooting through a portable power generator? Trashing the engine of a helicopter? Radar trucks? Missiles? Cannons? Large fuel tanks?