It seems there was another quirk that snuck in due to the internal max to maya conversion!
The axis difference between maya and max caused rotations in the ref file.
We updated the Weapons_REF_A.zip on the wiki to the new one
That should solve it.
(Also, I just updated the last patch notes. Forgot to mention we updated the export scripts to fix some general issues. Mainly animation export related, but also some general stability, so it's worth updating. You'll still have to single out one weapon from the file though.)