Gundrills range from 0.055 of an inch to 2.500 inches in diameter up to 72 in depth.small hole gundrilling, Gundrilling services available for various types of materials. Deep Hole Gun Drilling Services for the Medical, Firearms, Automotive and Aerospace Industries to Name a Few; Capabilities Include Diameters From. - .5 and 1/ - .00 in Length; Holes are Drilled in Finished and Semi-Finished Parts or Blanks and a Variety of Steel, Exotic Alloys and Plastics; Equipped with State of the Art Counter ...