Firearm bolt hold-open assembly and methods of use thereof

1. A bolt hold-open system comprising:

a block having a vertical slotted aperture positioned on the top surface of said block and removably mounted internally within a firearm receiver below a bolt assembly;

a lifter assembly removably positioned within said vertical slotted aperture having:

a top plate positioned beneath a bolt;

a tubular shaft having a top end, a bottom end, and defining an internal spring housing that is open at the bottom end and closed at the top end by the top plate;

a cross pin slot intersecting the spring housing;

a spring internally positioned within said spring housing;

wherein said lifter assembly is secured within said vertical slotted aperture by a cross pin inserted through a pin aperture on said block and said cross pin slot;

wherein a spring-loaded magazine follower engages and exerts an upward force on said lifter assembly; and

wherein the firing of the last round of a magazine generates an ejection force causing said bolt assembly to move rearward past said lifter assembly allowing said lifter assembly to extend upward and block a forward return motion of said bolt assembly.

2. The system of claim 1 , wherein said firearm receiver comprises a firearm receiver from an AK-47, or an AK-47 variant.

3. The system of claim 2 , wherein said block comprises a block having a plurality of match rivet attachment points.

4. The system of claim 1 , wherein said lifter assembly further comprises:

a bearing positioned within said spring housing and responsive to said cross pin; and

a coupler removably secured to the bottom end of the shaft enclosing the spring.

5. The system of claim 1 , wherein said top plate comprises a break tab and a bolt stop.

6. The system of claim 5 , wherein the magazine follower comprises a magazine follower having a flat spring extending upwards from the lower portion of the rear surface of a magazine, wherein said flat spring engages and exerts an upward force on said break tab.

7. The system of claim 5 , wherein said bolt stop of said lifter assembly engages the bolt assembly such that a return spring force of said bolt assembly holds said bolt against said bolt stop.

8. The system of claim 7 , wherein said bolt assembly further comprises a charging handle that releases the engagement between said bolt stop and said bolt.

9. The system of claim 1 , and further comprising a lifter release and engagement assembly that manually retracts or extends the lifter assembly.

10. The system of claim 9 , wherein said lifter release and release engagement assembly comprises a pull rod coupled with a handle assembly.

11. A bolt hold-open assembly comprising:

a firearm having a bolt assembly comprising a bolt and a bolt carrier;

a block having a vertical slotted aperture positioned on the top surface of said block and mounted internally within a firearm receiver;

a lifter assembly removably positioned within the vertical slotted aperture of said block having:

a shaft forming an internal spring housing and a cross pin slot;

a spring positioned with said spring housing;

at least one bearing positioned adjacent to said spring;

a top plate having a break tab and a bolt stop;

a cross pin inserted through a pin aperture on said block and positioned within said cross pin slot adjacent to said bearing forming a tractable coupling;

a coupler removably secured to a bottom end of the shaft and enclosing the spring and configured to allow insertion and removal of said spring from said spring housing;

wherein a magazine follower that engages the break tab of said top plate after the last cartridge of a magazine has been chambered exerting an upward force on said top plate against the bottom of said bolt; and

wherein firing of said last cartridge moves said bolt assembly rearward past said top plate allowing said top plate to extend upward blocking a forward return motion of said bolt assembly.

12. The device of claim 11 , wherein said firearm comprises an AK-47, or an AK-47 variant.

13. The device of claim 12 , wherein said block comprises a block having a plurality of match rivet attachment points.

14. The device of claim 11 , wherein the magazine follower comprises a magazine follower having a flat spring extending upwards from the lower portion of the rear surface of a magazine, wherein said flat spring engages and exerts an upward force on said break tab.

15. The device of claim 11 , wherein said bolt stop of said lifter assembly engages the bolt assembly such that a return spring force of said bolt assembly holds said bolt against said bolt stop.

16. The device of claim 11 , wherein said bolt assembly further comprises a charging handle that releases engagement between said bolt stop and said bolt.

17. The device of claim 11 , and further comprising a lifter release and engagement assembly.

18. The device of claim 17 , wherein the lifter release and engagement assembly comprises a pull rod coupled with a handle assembly that manually retracts or extends the lifter assembly.