Sinclair stainless steel neck turning and expander mandrelsfor 17 through 50 caliber cartridges are turned from highgrade stainless steel on precision turning centers. Turningmandrels are sized .002'''' under bullet diameter andexpander mandrels are .001'''' under bullet diameter. Theshape and surface of all of our mandrels is the result of years ofexperimenting by many expert handloaders. Our Carbide turning mandrelsare precision ground from solid carbide stock, which yields even closer tolerances. AllCarbide mandrels are ground to .002'''' under bullet diameter. Adjustments on our NT-4000turning tool will be more consistent withcarbide mandrels due to the tighter tolerancesof the mandrel Mfg: Sinclair International