Adjustable length heavy duty butt stock assembly for a firearm

An adjustable length butt stock assembly for a firearm comprising:

• an elongated receiver extension tube having a front end, a rear end, a longitudinally extending X-axis, a telescoping portion extending forwardly a predetermined distance from said rear end, a passive portion extending rearwardly a predetermined distance from said front end;
• an outer diameter D1, an inner diameter D2;
• said receiver extension tube having a radial thickness T1 and a length L1;
• said receiver extension tube having an outer top surface, an outer bottom surface, an outer left side surface and an outer right side surface;
• a plurality of longitudinally spaced length adjustment grooves formed in said outer bottom surface of said receiver extension tube;
• said length adjustment grooves being transversely oriented to said X-axis;
• a butt stock having a front end having a front wall surface, a rear end having a rear wall surface, a top wall surface, a bottom wall outer surface, a left side outer wall surface and a right side outer wall surface;
• a primary bore hole having a diameter greater than D1 extends inwardly from said front end of said butt stock for telescopically receiving said rear end of said receiver extension tube;
• a secondary bore hole extends traversely through said butt stock from said left side outer wall surface to said right side outer wall surface;
• said secondary bore hole having an interior outlet port that communicates with the interior of said primary bore hole;
• an elongated locking plunger pin having an outer end, an inner end and an arcuate outer side wall surface wherein said inner end of said locking plunger pin has an internally threaded bore that matingly receives an externally threaded front end of a push button lock/screw;
• and
• said push button lock/screw having an outer end having a head cap, a shank portion and said externally threaded front end
• locking means for locking and unlocking said locking plunger pin in said secondary bore hole with a portion of said arcuate outer surface of said locking plunger pin extending through said interior outlet port so that said locking plunger pin engages one of said adjustment grooves formed in said outer bottom surface of said receiver extension tube wherein said locking means comprises a push button lock/screw.