Helical Fluted Mini Bolt Knob Helical Fluted Mini Bolt Knob 1.5″ Long 0.700″ Major Diameter Tapered up from a 0.380″ diameter at the threads They feature 5/16-24tpi threads that are 0.650″ deep with a .100″ recess These also feature 6 Spiral flutes for optimal grip in the field Explore Firearm Solutions – J&A Outdoors
