Forster Case Trimmer Pilot Use the hardened and precision-ground Outside Neck Turner Pilot in place of the regular Case Trimmer Pilot. Order pilots (OT2XXX) separately. Pilots are made .0020" to .0025" smaller than the bullet's diameter. Forster Products offers many standard sizes, and custom-machined pilots are available for an additional machining fee. Do not confuse this product with the Hand Held Outside Neck Turner Pilots, which are not interchangeable. For caliber specific sizes, Click Here.