Your not looking at the carrier screws, those are most likely the shell guide screws. The carrier is nearly solid where the screws enter and inside screw heads would be nearly inpossible. The screws that are from the inside to the outside retain the cartridge guides. They are usually set a bit and cantankerous to remove and yea there are screw drivers that make 90 degree turns! Most hardware stores will carry something.. The one I use is actually a small ratchet that a Brownells screwdriver bit fits into. I would not reccomend removing those screws unless really necessary...