It's chambered in .45ACP with a 5Ó button rifled barrel supported by a full length guide rod. Smooth, angled, snag-free style allows for quick draw in fast need situations. Includes a low profile angled rear sight along with skeletonized hammer and trigger with adjustable over travel stop and ambidextrous safety standard in the Rock series. Finished with a tough, parkerzied matte coating and comes with checkered rubber grips. True to all Rock Island 1911s, it comes with a crisp factory 4- to 6-pound trigger, making it a great experience right out of the box