MULTIPART TRUNNION AND AMBIDEXTROUSLY MOUNTABLE BARREL FOR FIREARMS

1 . A trunnion assembly for a firearm, comprising:

a trunnion body defining an aperture extending therethrough; and

a trunnion insert configured to be secured in the aperture, the trunnion insert defining an interior space in which a barrel of the firearm is receivable to mount the barrel to the trunnion body when the trunnion insert is secured in the aperture.

2 . The trunnion assembly of claim 1 , wherein:

the interior space extends through the trunnion insert and includes an open forward end, an open rear end, and a passage extending from the open forward end to the open rear end;

the open rear end is configured to receive a bolt of the firearm; and

the open forward end is configured to receive the barrel therethrough and into the passage.

3 . The trunnion assembly of claim 1 , wherein:

the aperture of the trunnion body includes a front end and a back end; and

the trunnion insert is configured to be receivable in the aperture only when inserted into the aperture through the front end or the back end thereof.

4 . The trunnion assembly of claim 3 , wherein:

the trunnion insert includes a tubular body having a forward end, a rear end, and a flange extending radially outward from the forward end or the rear end; and

the flange is configured to index the trunnion insert within the aperture by engaging a surface of the trunnion body at the front end or the back end of the aperture.

5 . The trunnion assembly of claim 1 , wherein:

the aperture of the trunnion body includes a front end and a back end; and

the trunnion insert is configured to be receivable in the aperture only when inserted into the aperture through the back end thereof.

6 . The trunnion assembly of claim 5 , wherein:

the trunnion insert includes a tubular body having a forward end, a rear end, and a flange extending radially outward from the rear end; and

the flange is configured to index the trunnion insert within the aperture by engaging a surface of the trunnion body at the back end of the aperture.

7 . The trunnion assembly of claim 1 , further comprising:

at least one trunnion insert fastener receivable through the trunnion body and the trunnion insert when the trunnion insert is received in the aperture to secure the trunnion insert in the trunnion body.

8 . The trunnion assembly of claim 7 , wherein:

the trunnion insert defines a longitudinal axis and at least one opening extending therethrough at an angle to the axis;

the trunnion body defines at least one through hole extending therethrough which aligns with the at least one opening extending through the trunnion insert when the trunnion insert is received in the aperture of the trunnion body; and

the at least one trunnion insert fastener is receivable in the at least one opening and the at least one through hole to secure the trunnion insert in the trunnion body when the trunnion insert is received in the aperture and the at least one opening is aligned with the at least one through hole.

9 . The trunnion assembly of claim 2 , further comprising:

at least one barrel fastener receivable through the trunnion body and the trunnion insert when the trunnion insert is received in the aperture to secure the trunnion insert in the trunnion body and substantially prevent the barrel from rotating when the barrel is received in the passage.

10 . The trunnion assembly of claim 9 , further comprising the barrel, wherein:

the barrel defines a flat surface configured to be engaged by the at least one barrel fastener when the barrel is received in the passage of the trunnion insert; and

the at least one barrel fastener engages the flat surface to substantially prevent the barrel from rotating in the passage when the at least one barrel fastener secures the trunnion insert in the aperture of the trunnion body.

11 . The trunnion assembly of claim 9 , wherein:

the trunnion insert defines a longitudinal axis and at least one hole extending therethrough at an angle to the axis;

the trunnion body defines at least one through hole extending therethrough which aligns with the at least one hole extending through the trunnion insert when the trunnion insert is received in the aperture of the trunnion body; and

the at least one barrel fastener is receivable in the respective holes of the trunnion insert and trunnion body when the trunnion insert is received in the aperture and the at least one hole extending through the trunnion insert is aligned with the at least one through hole extending through the trunnion body to secure the trunnion insert in the trunnion body and substantially prevent the barrel from rotating when the barrel is received in the passage.

12 . The trunnion assembly of claim 2 , wherein:

the bolt includes at least one bolt lug thereon; and

the open rear end of the trunnion insert includes at least one locking surface configured to engage the at least one bolt lug when the bolt is in battery in the open rear end of the trunnion insert.

13 . The trunnion assembly of claim 2 , wherein:

the trunnion insert defines a longitudinal axis and includes first and second pluralities of non-helical, axially spaced barrel locking lugs, each plurality of barrel locking lugs spaced circumferentially around an interior surface of the open forward end of the trunnion insert from the other plurality of barrel locking lugs so as to define at least one keyway extending longitudinally along the interior surface between the first and second pluralities of barrel locking lugs.

14 . The trunnion assembly of claim 1 , wherein the trunnion body is configured to mount a feed mechanism of the firearm.

15 . The trunnion assembly of claim 1 , wherein the trunnion body and the trunnion insert lack screw threads.

16 . A firearm comprising the trunnion assembly of claim 1 , wherein:

the trunnion insert is secured in the trunnion body; and

the barrel is secured in the trunnion insert.

17 . A method of mounting a barrel to a firearm, comprising:

providing the trunnion assembly of claim 1 ;

securing the trunnion insert in the trunnion body; and

securing the barrel in the trunnion insert when the trunnion insert is secured in the trunnion body.

18 . A barrel assembly for a firearm, comprising:

a barrel;

a trunnion in which the barrel is receivable, the trunnion including a plurality of barrel locking lugs on an interior surface thereof; and

a barrel lug sleeve configured to be secured on the barrel and engaged with the plurality of barrel locking lugs to mount the barrel to the trunnion when the barrel lug sleeve is secured on the barrel, received in the trunnion, and rotated in either a clockwise or a counterclockwise direction about the barrel;

wherein the barrel and the trunnion lack screw threads.

19 . The barrel assembly of claim 18 , wherein:

the barrel includes an annular protrusion having a front face and a rear face;

the barrel lug sleeve is configured to be received against one of the front face or the rear face of the annular protrusion; and

the barrel assembly further comprises a barrel lug cap configured to be received against the other of the front face or the rear face of the annular protrusion and matingly engage the barrel lug sleeve to secure the barrel lug sleeve to the annular protrusion when the barrel lug sleeve is received against said one of the front face or the rear face.

20 . The barrel assembly of claim 18 , wherein:

the barrel locking lugs are non-helical and spaced so as to define at least one barrel lug keyway extending longitudinally along the interior surface of the trunnion;

the barrel lug sleeve includes a plurality of non-helical barrel lugs on an exterior surface thereof spaced so as to define at least one barrel locking lug keyway extending longitudinally along the exterior surface;

the barrel locking lugs pass through the at least one barrel locking lug keyway and the barrel lugs pass through the at least one barrel lug keyway when the barrel lug sleeve is inserted into the trunnion; and

rotation of the barrel lug sleeve in either the clockwise or counterclockwise direction when the barrel lug sleeve is received in the trunnion engages the barrel lugs with the barrel locking lugs to mount the barrel to the trunnion.