High heat treatment steel bushing for the recalibration of the collar.
 These bushings are hand polished with a hardened surface of RC 60-62 to reduce calibration efforts. Available sizes are calculated in 0.001 inch increments.
 Dimensions: 1/2 ″ OD x 3/8 ″ long
 Good collar tension is now recognized with a value of .002 or .003 lower than that of the finished cartridge, but there are two different measurement methods to choose the bushing that best suits your needs:
 PAY ATTENTION: all measurements and measurements (as well as the diameter of the bushing) are in thousandths of an inch.
 METHOD OF MEASUREMENT
 - measure the thickness of the collar (e.g. .015)
 - multiply this thickness by two (.015 × 2 = .030)
 - add the diameter of the ball (e.g. .308 + .030 = .338)
 - subtract .002 or .003 (depending on whether you use moly or Hbn coated balls) from the total and order the bushing with that number.