1. A firearm comprising a frame, a receiver mounted on said frame, a barrel mounted on said receiver, a bolt mounted in said receiver and telescopically movable relative to the breech end of said barrel, a firing pin fixedly positioned on a portion of the bolt so located relative to the breech end of the barrel as to come into contact with the free end of a cartridge of a round of ammunition in the breech end of the barrel upon release of the bolt from its open position, recoil spring means arranged to bias said bolt toward firing position, means including a trigger and sear movably mounted on said frame and operable to release said bolt from its open position to initiate a firing operation, a magazine mounted on said frame with its discharge portion adjacent the breech end of said barrel, a trigger guard fixedly mounted on said frame and having an intermediate portion extending from said frame outwardly and in enveloping relation to said trigger, said trigger guard being arranged with one end thereof disposed adjacent the discharge portion of said magazine and extending toward the breech end of said barrel for guiding rounds of ammunition into the breech end of said barrel prior to firing, and a bolt handle movably mounted on said bolt and protruding outwardly through a longitudinal slot formed in said receiver, said slot and said bolt handle being configured so as to prevent movement of said bolt relative to said receiver for one position of said bolt handle relative to said bolt and so as to accommodate movement of said bolt relative to said receiver for another position of said bolt handle relative to said bolt.

2. A firearm comprising a frame, a receiver mounted on said frame, a barrel mounted on said receiver, a bolt mounted in said receiver and telescoPically movable relative to the breech end of said barrel, recoil spring means arranged to bias said bolt toward firing position, means including a trigger and sear movably mounted on said frame and operable to release said bolt from its open position to initiate a firing operation, a magazine mounted on said frame with its discharge portion adjacent the breech end of said barrel, and a trigger guard fixedly mounted on said frame and having an intermediate portion extending from said frame outwardly and in enveloping relation to said trigger, said trigger guard being arranged with one end thereof extending inwardly into the interior portion of said frame through an opening formed therein and disposed somewhat to the rear of the breech end of said barrel and said one end of said trigger guard being configured to define an upwardly inclined path for guiding rounds of ammunition into the breech end of said barrel prior to firing.

4. A firearm comprising a frame, a receiver mounted on said frame, a barrel mounted on said receiver, a bolt mounted in said receiver and telescopically movable relative to the breech end of said barrel, recoil spring means arranged to bias said bolt toward firing position, means including a trigger and sear movably mounted on said frame and operable to release said bolt from its open position to initiate a firing operation, a magazine mounted on said frame with its discharge portion adjacent the breech end of said barrel, and a trigger guard fixedly mounted on said frame and having an intermediate portion extending from said frame outwardly and in enveloping relation to said trigger, said trigger guard being arranged with one end thereof disposed adjacent the discharge portion of said magazine and extending toward the breech end of said barrel for guiding rounds of ammunition into the breech end of said barrel prior to firing and said one end of said trigger guard being provided with lateral portions for engaging lower parts of said receiver and for affording support therefor.

5. A firearm comprising a frame, a receiver mounted on said frame, a barrel mounted on said receiver, a bolt mounted in said receiver and telescopically movable relative to the breech end of said barrel, recoil spring means arranged to bias said bolt toward firing position, a bolt handle movably mounted on said bolt and protruding outwardly through a longitudinal slot formed in said receiver, said slot and said bolt handle being configured so as to prevent movement of said bolt relative to said receiver for one position of said bolt handle relative to said bolt and so as to accommodate movement of said bolt relative to said receiver for another position of said bolt handle relative to said bolt, and a sight passage being formed in said bolt handle and arranged to accommodate sighting when said bolt handle is disposed in unlocked condition but not when said bolt handle is in a bolt locking position.