GUN Anybody running a free float tube?

Discussion in 'On Topic' started by pimpofthenation, Apr 30, 2009.

  1. pimpofthenation

    pimpofthenation OT Supporter

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    Excuse my AR noobness...

    I've got a Bushmaster free float tube on my 16" AR upper that I recently purchased. It doesn't appear to have anywhere to mount accessories. What are my options here?

    Replace it? Drill/tap my own holes? A rail that fits over the tube?

    Crappy pictar

    [​IMG]
     
  2. dpixel8

    dpixel8 New Member

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    I think they're ugly as fuck, and (though I don't know for sure) I would bet they don't dissipate heat very well
     
  3. If you like the tube style you can replace it with something like the JP modular piece. That'll give you lots of mounting options. You'll have to disassemble the upper to do that though. I imagine you have to disassemble the upper to remove that FF tube anyways. If you just want to mount stuff to that tube, you can drill and tap it, and depending on how thick and decent the metal is it could work just fine.
     
  4. pimpofthenation

    pimpofthenation OT Supporter

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    :dunno: Not really my thing either, but I could pass up the deal (complete 16" upper for $400, during the AR madness)
     
  5. pimpofthenation

    pimpofthenation OT Supporter

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    I'm planning on replacing the upper receiver with a flat top anyway... so I'll probably just do it all at once.
     
  6. Rip The Jacker

    Rip The Jacker New Member

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    i cant stand that look.
     
  7. dpixel8

    dpixel8 New Member

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    the one you have on there doesn't look like a FF rail. I'd just replace it with another 2-piece quad rail. :dunno:
     
  8. dpixel8

    dpixel8 New Member

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    it doesn't look FF. you sure it is?
     
  9. It is. I've seen quite a few of those handguards. The huge advantage of a 2 piece rail is that you don't have to take the upper apart to install, and I'm sure that upper has to be taken apart to get that handguard off.
     
  10. dpixel8

    dpixel8 New Member

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    gotcha
     
  11. dpixel8

    dpixel8 New Member

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    I've been putting off putting that FF rail and your low pro gas block on. though I know it's easy, I am A) lazy, and B) don't want to fuck it up :hsd:
     
  12. Just do it! It's not hard, as long as you take your time it'll be fine. And you'll feel good when it's done.
     
  13. pimpofthenation

    pimpofthenation OT Supporter

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    Yeah, it has to be taken apart. I've never done it. All part of the learning your rifle process :)
     
  14. dpixel8

    dpixel8 New Member

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    do I really need the torque wrench? I didn't think so as long as I get it tight and the gas tube holes lined up
     
  15. You'll need to unscrew your flash suppressor, since your barrel is 16+" it shouldn't be pinned or welded, so it should unscrew. Then punch out the gas tube roll pin so the tube can be pulled out of the FSB. Then punch out the FSB pins. They are tapered, so they only go out one way. I think it's left to right, but check to make sure. They can be tough to punch out, so make sure you support the barrel so it's not taking all the force of the hammering. Once they are out, the FSB should slide forward and off the gun. Take the gas tube out then too. From there you just have to figure how to get the FF tube off. If I designed it, I'd do it with a barrel nut that's threaded on the inside and outside and the tube just threads onto it. Look though and you should figure it out.
     
  16. dpixel8

    dpixel8 New Member

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    and if he can figure out who made it, most of them have FAQ's online
     
  17. I've seen people say the proper torque range is 30-80 ft-lbs. Basically, turn the barrel nut in until it won't go further by hand, then use the tool to twist it until the next gas tube notch is lined up. Some people like to torque it a little, then loosen it a few times to make sure everything is "bedded" together. 80 ft-lbs is pretty tight, so I wouldn't worry about exceeding that with the DPMS tool unless you are really giving it all you've got.
     
  18. It's a Bushy piece. I looked briefly on their website but didn't find anything.
     
  19. dpixel8

    dpixel8 New Member

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    figured as much
     
  20. pimpofthenation

    pimpofthenation OT Supporter

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    :bigthumb: thanks for the help guys. I'm going to try to do this next weekend.
     
  21. LancerV

    LancerV Something Happened OT Supporter

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    30ftlb is military spec
     
  22. LancerV

    LancerV Something Happened OT Supporter

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    If rifle barrel assembly (usually new) is not properly aligned In the upper receiver assembly (usually an old part),
    excessive windage will be present and the upper receiver assembly will require replacement to obtain the proper
    fit between the alignment pin and slot.
    3-42
    ARMY TM 9-1005-319-23&P
    AIR FORCE TO 11W3-5-5-42
    CAUTION
    Do not torque over 80 ft-lb (108 N-m) while tightening the barrel nut assembly to the next hole, to allow for
    proper alignment of gas tube.
    NOTE
    Do not attempt to hold the upper receiver assembly with a pry bar, however, If the rifle barrel assembly
    turns In the holding fixture, a pry bar may be used through the front sight assembly base to help prevent
    the rifle barrel assembly from turning In the holding fixture. Use care not to distort or bend front sight
    assembly or retaining pins. Use "buddy system" to hold pry bar.
    12. Torque the barrel nut assembly again to 30 ft-lb (40.5 N-m) while maintaining sight alignment. The barrel nut
    assembly may be tightened beyond 30 ft-lb (40.5 N-m) to align the barrel nut assembly serrations for proper gas
    tube clearance Never loosen the barrel nut assembly to align for gas tube clearance.
     
  23. john in jax

    john in jax New Member

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    If you really need to hang accessories and are uncomfortable changing out the tube there are a couple of companies making single, double and triple rails that clamp onto the barrel and/or front sight. It's a cheap way out in every sense of the word, but it works for lots of people.
     
  24. ZCP M3

    ZCP M3 Active Member

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    Love my JP VTAC handguard. Light, ergonomic, and very versatile! Would definitely recommend picking one up.
     
  25. ChipOnShoulder

    ChipOnShoulder New Member

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    A new flat top upper is $109, and a new carry handle is $60-110 depending on manufacturer. You'll want to check your barrel for M4 (extended) feed ramps.

    The worst possible combo is getting a barrel without M4 ramps, and mating it to a upper with M4 ramps. This creates a little gap where bullet tips can catch. Upper receivers without M4 ramps can be use on barrel extensions both with, and without M4 ramps.

    Changing a FF tube aint a big deal, but it may be a little difficult for a newbie. You'll be taking off the front sight base, and depending on your luck it may be easy as pie, or difficult as fuck. A BIG hammer, and a "trim nail punch", and soaking the pins in penetrating oil first (http://ai.pricegrabber.com/pi/71/66/35/716635235_160.jpg) will make removing the FSB's taper pins easy.

    You'll also need a replacement crush washer for your bird cage flash suppressor, as crush washers are one time items that are deformed after 1 use. If you don't want to bother with buying one locally, or paying $5 shipping on a 50 cent part, you can sand a used crush washer down until it can time correctly again.

    You'll need these things

    1. Bench Mounted Vise.

    2. Upper receiver action block. The "Panther Claw" is a favorite. If you have a flat top upper, you can improvise with wooden slats or a plastic cutting board... works perfect! I've only used flat top uppers, so never bought an action block.

    3. Punches. Trim nail punch for the front sight's two taper pins, a punch for the gas tube roll pin. I've never bought a set... just improvised with stuff in my garage.

    4. Hammer. A big one for the FSB removal process.

    5. AR Armorer's tool. Usually $35. This tool allows the removal/install of standard and standard FF barrel nuts, castle nuts, and use of torque wrenches (http://www.rainierarms.com/?page=shop/detail&product_id=421)

    6. Strap wrench. I've never used or examined a Bushmaster FF tube, but it looks like it's screwed directly onto the upper after a FSB is removed. A strap wrench (or a used timing belt with a vise grip. Yep i'm cheap) will aid in removing the tube itself.

    When reinstalling the barrel, the recommended procedure is to tighten-loosen the barrel nut three times... and on the last time torque between 30 and 80 foot pounds. At 100 foot pounds your upper receiver/barrel extension will break, as demonstrated by MilitaryMorons.com testing the Vltor gas block. I aim for 50.

    Good Luck!
     

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