When you ADS using the Cobra Sights on KA-74 and KA-101 the texture is missing from the surface closest to the player (presumably due to clipping?). This makes you see the weapon through the mounted optics, creating a very ugly effect. This does not happen when using Cobra Sights on KA-M. See attached screenshots of all three examples.
KA-M:
KA-74:
KA-101:
