are you sure you screw the rear screw "in" further to increase firing pin projection. When I screwed it in, I couldn't notice any increase in firing pin length, though it may be I just didn't percieve it getting longer.
That screw your talking about at the back of the bolt shroud adjusts the spring tension on the safety lever. It has nothing to do with firing pin protrusion. The firing pin protrusion is determined by where the shoulder stop on the firing pin meets the firing pin stop inside the bolt. This can only be adjusted by machining material off of either the firing pin stop on the firing pin itself or machining the internal stop within the bolt. It is easier to turn the reguired amount of material off of the firing pin as it is more complicated operation to remove it from inside the bolt. If your firing pin is protruding .035" from the bolt face and you want it to be .055 then you would need to remove .020" off of the firing pin shoulder stop. Before you have that done just make sure there is not a piece of dirt or brass shaving stuck in there preventing the pin shoulder stop from actually bottoming all the way on the shoulder stop inside the bolt.
