US Patent 7377066 Firearm with a readily interchangeable bolt face

A readily replaceable bolt face for a firearm (10) with a movable slide (12) that strips a round from a magazine, extracts the spent round from the firing chamber and then ejects the round from the firearm by means of an ejector. A bolt face insert (32) has an external configuration that is common to a range of calibers, but with a bolt face side (66) designed to fit the rim of a specific caliber or calibers having the same rim dimension. The insert may be replaced to fit a different caliber without replacing the slide. The bolt face insert is provided with a slot (62) for the ejector and a groove (60) to accept an extractor for the specified caliber.