These benchrest-quality barrels are made to impressive tolerances. Shilen's match barrels are uniform to .0003" in all dimensions. All match and select match barrels are air gauged on sensitive equipment, stress relieved and hand lapped at the factory. Shilen's barrels have probably set more world records than any other barrel made, because so many shooters rely on them. Requires threading to the action of your choice, crowning the barrel, and chambering by an experienced gunsmith.