The transfer port is 0.219" (7/32").... The barrel port is oval, 3/16" x 1/4" (same area).... The exhaust port in the valve is also 7/32".... The valve throat was 1/4" and the stem is 1/8", so teh resulting area was the equivalent of a 0.217" hole.... Now that the throat is drilled to 17/64' (0.266"), the equivalent would be 0.234".... The fact that I didn't gain any performance at any given pressure leads me to believe that the smallest area (ie everything except the valve throat area) is the limiting factor.... However, I did gain some efficiency, which makes me think that the larger throat allows less dwell to do the same job, which is a good thing.... The negative is that you then need a stronger hammer strike because of the increased seat area....

The Mr. Hollowpoint pellets look very nice, and are very consistent in size.... One weight didn't appear to shoot well, the others will have to wait until I get outside.... They are VERY expensive, however.... I am running a QB 7X hammer spring, a hammer (with guide) that weighs about 70 gr., and has about 0.85" of stroke before it hits the stem the way it is adjusted.... and the maximum valve lift possible at this adjustment is 0.2" (but in practice is much less)....

Bob