The threads on that adapter is 1/2-20 left hand. Yep, righty loosey lefty tighty. Really only works right with a BE Avenger, VL Revelation, and VL Triton 1. Later BE/VL guns had the same threads, but were right hand threaded.
If you want 1/8 npt to ASA look for a Spyder (old style) or Minicocker vertical adapter, something like this... PPS Aluminum Round ASA Stainless 1/8 NPT [TYPH089] - $15.00 : Palmers Pursuit Shop, Where Custom Still Means Something