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Question: Converting A-2 Stocked Rifle to a Tactical Stock

Discussion in 'Black Rifle Forum' started by cdog533, Dec 29, 2009.

  1. cdog533

    cdog533 Zombie Killer

    Oct 11, 2001
    I have a DPMS Bull 16 with a standard A-2 stock and standard A-2 big-ass buffer tube. pic below:

    Can I just remove this big metal buffer tube and add a short buffer tube in order to fit a Mag Pul or equivalent M4-style tactical stock? So I simply remove this tube with an M4 armorers tool and fit up the new one?

    Can I replace it with either a milspec or a commercial buffer tube? I think either will fit, but unsure.

  2. faawrenchbndr

    faawrenchbndr DirtyThirty fan CLM

    Nov 24, 2005

  3. bdh_1

    bdh_1 Millennium Member

    Apr 19, 1999
    Like FAA said, easiest to buy a kit. Otherwise you need a receiver end plate, receiver extension (mil-spec or commercial diameter as they will both thread into your receiver), castle nut, buffer, spring (buffers and springs are different for collapsible stocked rifles from an A2 fixed stock), and appropriate commercial or mil-spec sized stock along with the wrench that was mentioned.
    Last edited: Dec 29, 2009
  4. lawman800

    lawman800 Juris Glocktor

    I just did the exact same thing on my A1. Buy the whole telescoping stock kit that comes with the 6 position buffer tube, springs, castle nut, retaining plate, and don't forget the carbine wrench, you will not be able to tighten the castle nut on the retaining plate without the special carbine wrench. Brownells sells one for $8, you don't need the super expensive $70 version since you are not going to gunsmith for a living, are ya? You don't need a wrench for the A1/A2 buffer tube so don't worry about buying a combo wrench or another rifle specific wrench. You just need a 5/8" open socket wrench.

    There's a rectangular protrusion on the end of the rifle buffer tube and you wrench that gently to undo the tube. Mine came right off with minimal effort. Be careful, there are some small springs and pins that will fall out, including one inside the body that holds the buffer spring in place and another one that holds the pin that joins the upper to the lower. Without that pin, your bolt won't stay in place and will just pop out.

    My advice to you and what saved me was going to Youtube and searching for videos on how to do this. I found at least 4 good videos detailing what was needed to do, including a pretty good one by Midway Supplies and another one by Magpul, showing you how to install their UBR stock. If I didn't watch those videos, I would have lost a few pins and springs on the inside of the gun for sure.

    Lastly, be gentle! Nothing is worse than a tweaked lower if you damage it.
  5. jdm0506


    Feb 3, 2009
    Like the guys before, I'd recommend buying a stock kit. You'll save yourself a little money there, and I've been seeing some folks selling Magpul stock kits, which is nice. Mil and commercial spec aren't referring to the threads on the tube, so either will work. The important thing there is to ensure that the spec of your tube matches that of the stock. Most people prefer mil spec as different manufacturers for the commercial tubes have their own specs, leading to poor stock/tube fits.

    Like Lawman said, youtube videos are pretty helpful. First time I installed a collapsible stock, I was slightly confused. Basic process is thread castle nut onto tube, slide end plate on, screw tube into lower. Once the buffer detent is engaged by the tube, you want to make sure that the end plate is lined up properly with the receiver. You don't want it too tight as it will kind of "pinch" the buffer detent. Then just drop in your takedown spring and detent and begin tightening down on the castle nut. As others have said, be sure to get the wrench to properly tighten it, otherwise it is likely the castle nut will loosen (had it happen once when i didn't crank down enough with the wrench).

    I use the RRA wrench, which has an opening cut in it for removal and installation of an a2 tube as well. And it was fairly cheap. And don't forget to buy the proper buffer and spring for the tube as well, since the components in the A2 stock have significantly different dimensions. I'd recommend going to DSG Arms and buying their MOE kit (MOE pistol grip, handguard, and stock, as well as stock tube/buffer/spring/etc.) for $100 shipped.
  6. cdog533

    cdog533 Zombie Killer

    Oct 11, 2001
  7. furioso2112


    Dec 12, 2007
    BCM BCGs will serve you well. When I started building ARs, I had a couple issues with the stocks also - YouTube video is good advice, and don't force anything, and check and double-check things. The problems I ran into: not removing the plate, and wondering why the stock tube was so hard to turn...of course, taking the plate off and having the safety detent spring jump across the room...and not properly aligning the stock tube over the spring and bolt carrier detent (not the proper name, sorry, I forget at the moment) - this results in the little metal piece coming off, and then it mangles the spring. there are good pic-by-pic tutorials of the whole process on - AR15 tab, then build it yourself, then the sticky near the top, titled something like 'assemble your own...upper/lower/stock etc.'.

    I don't recommend loc-titing the castle nut. Others may disagree, or have an explanation of why not to. It is possible to use a hammer and punch, but you risk marring your gun (if) when you slip and drive the punch somewhere you didn't want to. The $8 wrench is fine - at least look at the DPMS multi-tool, though, if you think you might do other things. It has a lot of useful tools on it, and is sturdy. If you know you won't ever need anything else on it, save the extra $27.

    If you are really looking to stay inexpensive, BCM's extractor upgrade kits will get you a ways with many inferior-to-BCM bolts, and a single one is $5, pack of 3 is $12, IIRC. I replaced the springs in my Bushy and generic bolts with them, but left my Young Mfg. NM bolt as it came.
  8. lawman800

    lawman800 Juris Glocktor

    Isn't purple loctite the one for working screws that you can loosen for maintenace?
  9. RMTactical

    RMTactical CLM

    Oct 7, 2000
    Behind an AR-15
    Yep, you can do that. It's easy.
  10. bdh_1

    bdh_1 Millennium Member

    Apr 19, 1999
    The link you posted is for a commercial receiver extension. No locktite on the castle nut or receiver extension. You don't want to glue the nut to the RE or glue the nut to the receiver end plate. A small center punch, even an automatic one, and light hammer blows will move metal into the recesses in the nut.
  11. MySiK26

    MySiK26 ******

    as far as the bcg. Order one and keep it on hand if you'd like, you may be surprised how long that stock one will run. if you have extractor problems, just get an upgrade kit?
  12. cdog533

    cdog533 Zombie Killer

    Oct 11, 2001
    Stock - I did get a mil-spec stock/buffer kit from Spikes. I need to install it. The Youtube videos didn't really seem to address this. Anyone know of instructions specific to removing an A2 stock and replacing with typical M4?

    BCG - They DMPS staking is questionable. Plus extractor needs the upgrade. Bolt is likely questionable. My thought would be just to get a Bravo BCG and for $130 or so, I've really upped the reliability of the rifle. Then, I'll toss the DPMS BCG in a bag and THAT's the spare. Or use it as a barter item post-TEOTWAWKI.

    I'l post a pic when I get it done.
  13. lawman800

    lawman800 Juris Glocktor

    There is a video, but simply put, unscrew the buttpad, then you can slide off the A2 stock to expose the tube. The end of the tube has a protrusion which fits a 5/8" open socket wrench. Unscrew tube. Mne only took a little twist, then you can do the rest by hand.

    You have to watch out for the spring inside the stock and the buffer spring retaining pin knside the receiver. Other than that, it's quite simple.