Looking at both your threads there are a few things you might try to see if they help. Single feed a few cases and make sure your not getting some of the scratches from feeding out of the mag box. Make sure the chamber and cases are degreased and dry. Could try some bore paste on a patch rapped brush to buff the chamber, you don't want to polish to much but it would clean up the brass. The marks in the chamber don't look any worse than the boring marks on the lands which your smith has no control over. The lead cut looks really good to me, also the cross hatch marks which I assume is from trying to smooth the chamber don't look much better than the rest of the chamber. I will say your smith is trying to be accommodating, you need to keep him in the loop in regards to ordering a reamer. I would get a reamer print and have him give the ok before ordering. Not being a SAAMI chambering it is going to take some homework.