Hmm, I first installed my new edition JSAR SS valve unregulated and was getting about 940 fps average with the JSB 34 grain pellets (67 fpe). I have the JSAR MDS hammer, striker is set so that face of striker is flush to the face of the hammer, it does not protrude. Stock spring. I could get 16 shots. My rifle is a .25 caliber.
I regulated with the Houma and XXL plenum and Tim Hill gage manifold. I now have the TSS installed. I drilled the barrel to .196 and am using a poly type TP. I set the regulator for 2,000 psi. I get now 16 shots at 890 with the JSB 34 grain pellets (60 fpe) but instead of a fairly peaked bell curve unregulated the velocity is flat. If the rifle sits for several days the first shot will be slightly low but consistent thereafter.
JSAR side lever receiver, JSAR aluminum tube, JSAR MDS buffer hammer set flush, JSAR TSS, Houma reg with XXL plenum, Tim Hill gage manifold, Tim Hill short shroud, DFL adapter, DFL mod, poly tube TP and barrel drilled to .196 port, reg set at 2,000 psi, 5.9 pounds bare:
I can push it up to 70 fpe but accuracy begins to go (still decent) and one magazine+1 is all it has.