XX Grade; Hand-Selected For Uniformity To Within .0001"
Every barrel is precision, instrument-inspected for absolute straightness and, air gauged for maximum uniformity to yield the greatest accuracy possible. Land and groove tolerance from breech to muzzle can vary only .0001". Only a barrel that meets these demanding criteria wears the XX Premium stamp.
Big Book Catalog, Issue:70, Page:166
SPECS: Stainless or 4140 chrome moly steel, #7 contour, 27½" (69cm) long. Muzzle end marked for tightest taper. Not chambered or threaded. X-Long Unfinished blank 30" long.