better to let the parts wear into each other (mesh) in time, with use and a good lube, than to try and buff out or fit to or in , a "jig" ,made to put the parts as the drawings call for ,instead of "fit" to each other, yes, time and use does this all over the period of use and break in......spend the money and time on good ammo or range time cost..................
we used to use 'Lubriplate', the stuff for camshafts/lifters, to fit meshing parts together,but then we had this all left over from our old engine building days back in the 60's 8) :roll: :wink: