These are some of the results I got with mine, but I had fitted a Delrin guide and smoothed/polished every thing that touched anything else.
RWS Super H-Point 6,9gr ave. = 400fps
H&N Econ II 7.48gr ave. = 403fps
H&N Excite Hammer 7.87gr ave. = 385fps
Field Target Trophy 8.64gr ave. = 353fps
Hope this helps.