fosscad/Rifles/AR-15_Orion_PDW_Stock-WarFairy

The Orion AR-15 PDW Stock

Author

WarFairy

Description

This stock is mean to shorten the AR-15 while giving more adjustability to the length of pull, with the User notching the stock arms to make it the perfect length for their particular arms.

This will be an involved build, and not for the light hearted. That being said, it is worth it.

Materials

You will need some tools, ABS Cement or Epoxy, two 12" rods, and the spring from a standard M4 stock (or suitable replacement):

• An AR-15 Armorer's tool to tighten the Castle Nut on the Buffer Tube or False_Buffer_Stubby. (9.99 USD) http://www.brownells.com/gunsmith-tools-supplies/rifle-tools/wrenches/ar-15-m4-stock-wrench-prod16882.aspx
• A Hacksaw to trim excess length. (Optional, Length of pull with 12" rods is just short of 15.5")
• Sandpaper to rough surface of rods for gluing.
• Permanent marker for marking index points.
• 1/4" (0.25") thickness hand file (17.79 USD): http://www.mcmaster.com/#4254a27/=qnsz81
• Alternately: A Dremel or other tool may be used, so long as it is capable of creating a 1/4" wide .079" (2mm) to .098" (2.5mm) deep notch in your chosen stock arms.
• 2x 12" long 3/8th" (0.375") Diameter Rod - Steel, Aluminium, Carbon Fiber, or other stiff material:
  • Steel (8.19 USD): http://www.mcmaster.com/#8279t26/=qnt0ra
  • Aluminium (8.18 USD): http://www.mcmaster.com/#9062k281/=qnt22o
  • Carbon fiber (24" rod, will have to be cut, 14.30 USD): http://dragonplate.com/ecart/product.asp?pID=4515&cID=18
• M4 Stock Lock Spring (1.70 USD): http://www.brownells.com/rifle-parts/stock-forend-parts/stock-hardware/springs/m4-lock-spring-prod26515.aspx?ctl00$ucheaderSearch$btnSubmitSearch=Search

NOTE: If you are using an upper receiver that requires a buffer and action spring in the buffer tube, do not print the False_Buffer_Stubby. Your firearm will not function with it installed. If you are using an upper receiver that does NOT require a buffer, such as the RRA PDS Carbine, ARAK-21, LR-300, OA-93 or a regular upper with a CMMG Style .22LR conversion, print the False_Buffer_Stubby to get the shortest package possible (27" OAL with 16" barrel).

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Assembly Instructions

1. Install the 12" Rods into the two holes on the Butt Plate and set aside. Do not glue arms into place yet. The arms will be indexed before gluing.
2. Place Locking_Arm into the hole between the rings on the Stock_Body. Arms should slot into the recess between the slots to allow the locking tab on each arm to protrude 2mm into the stock arm channels. Turn Stock_Body assembly over and place M4 Stock Lock Spring onto tail of the Locking_Arm. Test fit the Lock_Button onto the tail of the Locking_Arm and test for tension on the spring. It should be slightly stiff to allow solid locking on the Stock Arms. Trim material from far end of the tail until spring has constant tension when the button is not depressed. Remove Button and spring, and set aside for final assembly.
3. Place Castle nut for standard buffer tube in between upright rings of the Stock_Body, with the flat surface pointing towards the ring with the tab sticking up from the bottom.
4. Place the Mil-Spec Buffer Tube or False_Buffer_Stubby, threaded end, through the ring without tab and thread fully onto the threads until you can go no further. Thread Buffer Tube or False_Buffer_stubby into the Buffer Tower of your selected lower until the nub on the Stock_Body indexes with the Buffer Lock Hole on your lower as closely as possible. Thread castle nut down to lock Stock_Body onto lower, indexed in the upright position (flat surface on top of rings pointing upwards and level with flat on buffer tower).
5. Slide Butt_Plate assembly with 2x Stock Arms through the channels of the stock body until forward face of Butt_Plate rests against buffer tube or False_Buffer_Stubby. This is your short index point. Mark the Stock Arms against the front face of the stock body. This Mark will be used with the Notching_Guide to make the indexing slot in the stock arm.
6. Repeat this process for every length you want the stock to index to. I.E. Slide the stock out three inches and mark both stock arms against the forward face of the Stock_Body. When maximum length desired is reached, make your final marking on the stock arms and remove the stock arms and butt plate from the lower receiver.
7. Remove the Stock_Arms from the Butt_Plate and place both into the respective receptacle channels in the Notching_Guide. Start with the last mark made, being the longest Length of pull desired. Place mark on the OUTSIDE of the Notching block, against the front face as if you were going to mark it again. Your notch will be in the groove in front of the Arrow. Using a hacksaw (if excess is to be removed) saw off excess length at the forward face of the Notching_Block. This will leave the stock arms flush with the forward face of the Stock_Body when the stock is fully extended.
8. Using the hand file or other tool with 1/4" width, file down the rods until they are flush with the bottom of the channel. Take special care to not allow the rods to rotate while notching.
9. Repeat this process with each of your index points, placing your marks against the forward face of the Notching_Guide.
10. You should now have 2x notched rods, with notches level with every other notch on that rod.
11. Gently rough 0.4" to 0.5" of the rod that will be glued into the recess on the Butt_Plate, and gently rough the inside surface of the recesses of the Butt_Plate. Glue roughed surface of the rods and place into recesses, taking special care to keep the notches facing upwards so that the lock arm may lock into them. Slide the Butt_Plate assembly into place on the firearm so that the arms are held in place during curing.
12. While glue is curing, fold a piece of paper several times to create enough thickness to hold gentle pressure downwards on the Locking_Arm by putting pressure on the Castle Nut. Place spring onto lock arm shaft and place a dab of glue into the hole in the Lock_Button. DO NOT OVER APPLY. Place Lock_Button onto Locking_Arm and press into place. It is highly recommended to use a clamp or something to prevent spring pressure from moving the button out of place during curing.
13. Wait 24 hours for glue to cure. .14 Once all glue is cured, your stock is ready to be used. To adjust, press the button on the underside of the Stock_Body and slide stock to desired length. The Locking_Arm will hold it in place.

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NOW! GO FORTH AND SHOW OFF YOUR UBER AWESOME STOCK TO ANYONE THAT WILL LOOK!

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Author Notes:

For Bug Reports, Criticism, Praise (I live for the Applause... Applause... Applause), concerns or tech support, please go to www.fosscad.org and click on the Chat link at the top. We have people in there at almost every hour of the day that will be absolutely happy to help you or pass word to the designer of any issues. Tor is supported and recommended! If you wish to chat using an IRC Client, irc.oftc.net #fosscad

And as always: You are Free. Act like it.