This exceptionally accurate Shaw barrel is precision reamed, button rifled and air gauged. This heavy match barrel has a .920" diameter with a 1 in 16" twist. Featuring a Bentz chamber, this replacement barrel will facilitate reliable feeding for countless days of fun at the range. The Bentz chamber is a match-type chamber for semi-autos. It is not as tight as a true, minimum-spec match chamber, but is much tighter than a sporter chamber. You will see much better accuracy with standard ammunition (in the 1000-1400 FPS range).