Firearm barrel having cartridge chamber preparation facilitating efficient cartridge case extraction and protection against premature bolt failure

A one piece barrel of a firearm, comprising:

• a barrel bore being defined within said barrel;
• a cartridge chamber being defined within said barrel and having communication with said barrel bore, said cartridge chamber having a tapered internal body wall surface, said cartridge chamber having a conical cartridge case shoulder support and sealing surface extending from said tapered internal body wall surface and having a cartridge case neck support and sealing surface having substantially circular intersection with said conical cartridge case shoulder support and sealing surface, said conical cartridge case shoulder support and sealing surface and said cartridge case neck support and sealing surface providing sealing with a cartridge and substantially preventing incursion of cartridge gas pressure into said cartridge chamber upon cartridge firing;
• and
• said generally tapered internal body wall surface of said cartridge chamber being defined by a plurality of circumferentially spaced internal elongate land surface segments having a predetermined diameter and a plurality of elongate circumferentially spaced internal relief surface segments having an internal diameter greater than said predetermined diameter and having edges being smoothly merged and contiguous with adjacent ones of said elongate circumferentially spaced internal land surface segments.

A firearm barrel having a one piece breech end and a barrel bore, comprising:

• a cartridge chamber being defined within said one piece breech end and having an internal configuration corresponding to the external configuration of the cartridge case of an ammunition cartridge and having a tapered body wall surface an internal conical cartridge case shoulder support and sealing surface and a cylindrical cartridge case neck support and sealing surface;
• said tapered body wall surface being partially defined by a plurality of substantially evenly spaced internal elongate tapered land surfaces having longitudinal edges and being engaged by a correspondingly tapered cartridge case positioned within said cartridge chamber;
• and
• said tapered internal body wall surface being partially defined by a plurality of substantially evenly spaced elongate tapered relief surfaces having longitudinal edges merging smoothly with said longitudinal edges of said elongate tapered land surfaces and extending radially outward beyond said evenly spaced elongate tapered land surfaces and having spaced relation with a tapered cartridge case positioned within said cartridge chamber.