Quick take-down barrel system and method for modular rifle

1. A modular rifle system comprising:

a lower receiver assembly;

an upper receiver assembly; and

a barrel assembly;

wherein the barrel assembly is releasably attached to a first portion of the upper receiver assembly by a barrel nut connector sleeve capable of being tightened by hand, the connector sleeve is prevented from becoming untightened and unconnected during firing of the rifle system by a second portion of the upper receiver assembly, and the second portion of the upper receiver assembly is releasably attached to the barrel assembly and the first portion of the upper receiver assembly,

wherein the second portion of the upper receiver assembly is releasably attached to the barrel nut connector sleeve by means of a take-down pin inserted through the second portion of the upper receiver assembly and engaging is receptacle groove in the barrel nut connector sleeve; and

wherein the second portion of the upper receiver assembly is releasably coupled to the first portion of the upper receiver assembly by means of an alignment tab and an alignment tab receptacle, wherein the second portion of the upper receiver is prevented from rotating during firing of the rifle system by coupling of the alignment tab and alignment tab receptacle.

2. A modular rifle system comprising:

a lower receiver assembly;

an upper receiver assembly; and

a barrel assembly;

wherein the barrel assembly is releasably attached to a first portion of the upper receiver assembly by a barrel nut connector sleeve capable of being tightened by hand, the connector sleeve is prevented from becoming untightened and unconnected during firing of the rifle system by a second portion of the upper receiver assembly, and the second portion of the upper receiver assembly is releasably attached to the barrel assembly and the first portion of the upper receiver assembly,

wherein the second portion of the upper receiver assembly is releasably attached to the barrel nut connector sleeve by means of a take-down pin inserted through the second portion of the upper receiver assembly and engaging is receptacle groove in the barrel nut connector sleeve; and

wherein the second portion of the upper receiver assembly is releasably attached to the barrel nut connector sleeve by means of a slotted screw clamp, wherein compression of the screw clamp on the barrel nut connector sleeve prevents the barrel nut connector sleeve from rotating during firing of the rifle system.

3. The modular rifle system of claim 1 , wherein the second portion of the upper receiver assembly is releasably attached to the barrel nut connector sleeve by means of a slotted screw clamp, wherein compression of the screw clamp on the barrel nut connector sleeve prevents the barrel nut connector sleeve from rotating during firing of the rifle system.

4. The modular rifle system of claim 3 , wherein the rifle system is an M-16 or AR-15 style rifle system.

5. A modular rifle system comprising:

a lower receiver assembly;

an upper receiver assembly having a first portion and a second portion; and

a barrel assembly, consisting of a barrel and a hand-tiqhtenable barrel nut connector sleeve;

wherein the barrel assembly is releasably attached to the upper receiver assembly by:

the hand-tightenable barrel nut connector sleeve releasably connecting the barrel assembly to the first portion of the upper receiver;

the second portion of the upper receiver assembly releasably attaching to the barrel nut connector sleeve and the first portion of the upper receiver assembly, wherein the second portion of the upper receiver assembly secures the barrel nut connector sleeve by means of applied pressure, preventing the barrel nut sleeve from rotating and the second portion of the upper receiver assembly from becoming detached when the rifle system is fired,

wherein the second portion of the upper receiver assembly is releasably attached to the barrel nut connector sleeve by means of a take-down pin inserted through the second portion of the upper receiver assembly and engaging a receptacle groove in the barrel nut connector sleeve; and

wherein the second portion of the upper receiver assembly is releasably coupled to the first portion of the upper receiver assembly by means of an alignment tab and an alignment tab receptacle, wherein the second portion of the upper receiver is prevented from rotating during firing of the rifle system by coupling of the alignment tab and alignment tab receptacle.

6. The modular rifle system of claim 5 , wherein the second portion of the upper receiver assembly is releasably attached to the barrel nut connector sleeve by means of a slotted screw clamp, wherein compression of the screw clamp on the barrel nut connector sleeve prevents the barrel nut connector sleeve from rotating during firing of the rifle system.

7. The modular rifle system of claim 6 , wherein the rifle system is an M-16 or AR-15 style rifle system.

8. A method of assembling and disassembling a barrel of a modular rifle system having an upper receiver assembly and a removable barrel assembly, comprising the steps of:

aligning the barrel assembly with a first portion of the upper receiver;

releasably affixing the barrel assembly to the first portion of the upper receiver assembly;

releasably securing affixment of the barrel assembly by means of a hand-tightenable barrel nut connector sleeve;

aligning a second portion of the upper receiver assembly with the first portion of the upper receiver assembly;

releasably connecting the first and the second portion of the upper receiver assembly;

releasably attaching the second portion of the upper receiver assembly to the barrel nut connector sleeve, wherein the second portion of the upper receiver assembly secures the barrel nut connector sleeve from rotating and the second portion of the upper receiver assembly from becoming detached during firing of the rifle system,

wherein the barrel assembly is releasably secured to the first portion of the upper receiver assembly by threading the barrel nut connector sleeve onto a threaded nipple on the forward face of the first portion of the upper receiver assembly and tightened by hand to secure the barrel assembly to the first portion of the upper receiver assembly;

wherein the second portion of the upper receiver assembly is releasably coupled to the first portion of the upper receiver assembly by aligning and inserting an alignment tab on one portion of the upper receiver assembly into an alignment tab receptacle on the other portion of the upper receiver assembly, wherein the second portion of the upper receiver is prevented from rotating during firing of the rifle system by coupling of the alignment tab and the alignment tab receptacle; and

wherein attaching the second portion of the upper receiver to the barrel nut connector sleeve is accomplished by inserting a removable pin through the second portion of the upper receiver assembly, in which the pin engages a receptacle groove integrated into the outer diameter of the barrel nut connector sleeve.

9. The modular rifle assembly/disassembly method of claim 8 , wherein the second portion of the upper receiver assembly is releasably attached to the barrel nut connector sleeve by tightening a slotted screw clamp around the outer diameter of the barrel nut connector sleeve, wherein compression of the screw clamp on the barrel nut connector sleeve prevents the barrel nut sleeve from rotating during firing of the rifle system.

10. The modular assembly/disassembly method of claim 9 , wherein the rifle system assembled/disassembled is an M-16 or AR-15 style rifle system.