Gasp-- On Topic RAM question!

The U.S. had a radar guided missile called BAT deployed towards the
end of WWII. The source material I've read claim that it sank a
Japanese DD, as well as hitting a bridge and it had a ragne of about
20 MI.
Forgive me for being suspicious, but that seems like *incredible*
performance for a radar guided weapon in WWII, given that I doubt many
homing radar missiles of the 1960's coudl be used both on bridges and
ships, to say nothing of a 1945 missile.
Does anyone have any more information about it, and more
importantly, why if it existed, did the Russians beat us to the punch
with the Styx?