They haven’t abandoned it, but there are a number of reasons for and against its’ use.
Grid fins allow high angles of attack, great precision, and lower torque from the control actuators.
They also have wave drag issues in transonic regions, and have a very large relative RCS.
These are not super beneficial in modern day because radar based MAWS allows users sufficient warning to successfully evade or decoy such ordnance. Interestingly, if the grid fins can be made to fold it makes for better storage space, however most modern missile designs are wingless.
Why? That just seems like a waste of time. There is never going to be a situation in which the missile is not going to have its fins installed when fired.
BBCRF is estimating the increase in drag due to the fins addition, this will give us an estimate of how much higher the drag should be for R-77 over other similarly sized missiles in the game.
That isn’t true, AIM-120 is underperforming in both front and rear aspect conditions at high launch speed / altitude as well.
At launch speeds above ~1.3 mach it heavily underperforms because it lacks dynamic drag coefficients. It is adjusted currently to meet launch ranges expected from subsonic launch, which by nature, include the wave drag that wouldn’t occur at higher speeds.
