Aimpoint's ACRO leaves a small gap between the sight and an in spec ACRO milled slide footprint or adapter plate. The void is the result of the locking bar slot on the plate being deeper than the locking bar below the sight. The gap is normal, and can be found below an ACRO P1 or P2 and an in spec ACRO plate, milled slide or mount.
An ACRO P2 mounted on a B&T Picatinny adapter. Two gaps are seen here, as the B&T mount is reversible, and has two locking bar slots.
Below is an ACRO P2 mounted on an OPF-G, ACRO plate. A milled slide ACRO footprint and adapter plate has a single locking bar slot.
Also observed is the different amount of gap between the left and right side of the ACRO P2 when mounted. When the sight is mounted on an in spec plate or footprint, the left side appears to have a smaller gap than the right, this is due to the P2's locking bar clamping onto the dovetail of the plate or a milled slide's ACRO footprint, and the locking bar is slightly tilted when viewed from the front or rear. This too, is normal.
