RIMFIRE BLANK ADAPTOR KIT FOR M16 RIFLES

• US H926 H
• Filed: 11/16/1990
• Issued: 06/04/1991
• Est. Priority Date: 11/16/1990
• Status: Abandoned Application

• Current Assignee: Raymond A. Mahtook
• Original Assignee: Raymond A. Mahtook
• Inventors: Mahtook, Raymond A.
• Primary Examiner(s): Wendtland, Richard W.
• Application Number:
  US76/182,00
• Time in Patent Office: 200 Days
• Field of Search: 042077, 0890145, 089029, 089128, 089180
• CPC Class Codes: F41A 11/02 Modular concepts, e.g. weapon-family concepts

Abstract

A conversion kit for allowing an M16 rifle to fire .22 caliber ball and bk ammunition in semi-automatic and automatic firing modes, comprises a bolt replacement which replaces the standard bolt in the rifle. The bolt replacement moves in the rifle receiver and is engageable with a sear trip bar of the conversion kit. The sear trip bar interacts with an automatic sear of the M16 rifle to permit automatic fire. A spring loaded detent is provided in the conversion for engaging a detent slot in the replacement bolt, to hold the bolt face against a chamber insert, to avoid bouncing of the bolt for automatic and burst firing modes. For the firing of blank cartridges, a shaft is provided in a chamber insert for reducing the diameter of the chamber insert to preclude the feeding of ball cartridges. An orifice in the shaft allows for escaping gases to leave the blank cartridge, but produces back pressure so that the replacement bolt can be cycled for blow back operation.

Claims

1. A conversion kit for a rifle having a full chamber for seating a full size cartridge, a receiver behind the full chamber, a standard bolt movable along a path in the receiver for feeding a full cartridge to and firing a full cartridge in the full chamber to conduct a gas activated firing cycle for the rifle, and an automatic fire sear connected to the receiver and movable into the path of movement of the standard bolt for engagement by the bolt during a firing cycle to produce automatic gas activated firing of the rifle, the conversion kit comprising:

a chamber insert adapted to be fixed in the full chamber and defining a reduced chamber for seating a reduced size cartridge;

a replacement bolt adapted for movement in the receiver behind said chamber insert for feeding a reduced cartridge to and firing a reduced cartridge in said reduced chamber to conduct a blow back activated firing cycle;

a sear trip bar engagable by said replacement bolt and positioned to engage the sear of the rifle when the sear is in the path of movement of the standard bolt so that said sear trip bar engages the sear to produce automatic blow back firing of the rifle with reduced cartridges; and

detent means connected to said chamber insert for engaging and momentarily holding said replacement bolt against said chamber insert when said replacement bolt strikes said chamber insert during a firing cycle to prevent bouncing of said replacement bolt from said chamber insert during automatic blow back firing of the rifle.

2. A conversion kit according to claim 1 including a guide rail adapted to be positioned in the receiver for guiding the movement of said replacement bolt, said detent means comprising a pocket defined in said guide rail, a detent mounted for movement in said pocket, in a direction substantially transverse to the direction of movement of said replacement bolt, biasing means for biasing said detent toward said replacement bolt, and a detent slot in said replacement bolt for engagement by said detent when said replacement bolt is against said chamber insert.

3. A conversion kit according to claim 2 wherein said replacement bolt includes a face for engagement against said chamber insert, said face including a shallow chamfer for engagement with said detent to move said detent into said pocket.

4. A conversion kit according to claim 3 wherein said sear trip bar is mounted to said guide, said replacement bolt being engagable with said sear trip bar for moving said sear trip bar into engagement with the sear of the rifle.

5. A conversion kit according to claim 4 including a shaft mounted in said reduced chamber for reducing the effective diameter of said reduced chamber to a diameter for receiving blank cartridges but precluding ball cartridges.

6. A conversion kit according to claim 5 wherein said shaft includes a bore of a diameter to receive a blank cartridge and an orifice which is smaller in diameter than said bore for constricting discharge gases from a blank cartridge when fired by said replacement bolt.

7. A conversion kit according to claim 1 including a shaft mounted in said reduced chamber for reducing the effective diameter of said reduced chamber to a diameter for receiving blank cartridges but precluding ball cartridges.

8. A conversion kit according to claim 7 wherein said shaft includes a bore of a diameter to receive a blank cartridge and an orifice which is smaller in diameter than said bore for constricting discharge gases from a blank cartridge when fired by said replacement bolt.

9. A conversion kit according to claim 1 wherein said replacement bolt includes a face for engagement against said chamber insert, said face including a shallow chamfer for engagement with said detent to move said detent into said pocket.

10. A conversion kit according to claim 9 wherein said sear trip bar is mounted to said guide, said replacement bolt being engagable with said sear trip bar for moving said sear trip bar into engagement with the sear of the rifle.