I never had any problems running the newer black screws down by hand in my RM100. Now with the RM50C chassis i got, I can't run any of the black ones I have in every module down by hand. Have to use a screwdriver and one is inevitably going to break. I have one pair of the original bigger head stainless ones and they run down perfectly in both heads. Anyone had this problem? I bought a 10 pack of the stainless ones from amazon but they were the wrong ones ($18 shipped wasted.. Ugh).. Getting ready to find a #4-40 tap and chase the threads..