Quickfire -- get within 70, point them in the right direction, let them home in. For the tests above I was within 20k to rule out any fuel shenanigans with the projectile itself.
Edit: Nevermind, repro on pg also. This is a bit inconsistent, which is weird all by itself. Missile guidance seems to be tracking something that isn't there. Doing a round of tests with Bx points as well