.177 JSB 13.4 RD-max speed?

I have a 177 Vulcan II that came shooting 10 gr about 800 FPS , Just adjusting the hammer spring I have a little over 900, about 910 FPS ,,, The faster I shot the 177 pellets the better the gun shot, More accurate, I am sure I would have to get to the regulator to get any more FPS out of her. Its not pellet fussy at all, Seems to like just about any think I shoot, 

Mike
 
When shooting them in my Pulsar HP and its 3 settings, I saw the following. 

13.43 Redesigned (only tried med and high before today)

  • Low = 818 FPS. Loved them. Nice light hold and did great!! Pellets hitting the same spot with few fliers. I wish I had tried this setting before!
  • Medium = 925 FPS. Very Firm hold only. Low was still better. Had some promise on a few shots, but not consistent enough to use regularly.
  • High = 1014 FPS. No go. Very Firm only to get pellets to have any level of consistency, but not good. ES and SD was actually better than low and medium but worst performing of the 3. 

I reached out to SorenSD to get some thoughts from him because he has a lot of documentation on a RW (which is very close). He said his rifle likes them around 900FPS and not much more.
 
My RW shoots them at 798-800fps on low 900fps on Med. (stayed stable out to 100yds!) which it shoots pretty well @ 50yds plus! If I shoot 25m it’s low power all the way! It shoot’s the reg. 13.4’s at 817-820fps, which is right at the 20ftlb limit I was a little surprised that it would shoot RD’s accurately that slow? My R.A.W. won’t shoot them unless they are at 830 plus