Aluminum Barrel Nut

Discussion in 'Gunsmithing' started by redneckclimbing, Apr 16, 2013.

  1. redneckclimbing

    redneckclimbing Well-Known Member

    Messages:
    240
    Joined:
    Jan 24, 2012
    Has anyone tried an aluminum barrel nut before. I am wanting to build an ULTRA light .260 rem on a rem 700 SA.

    Before anyone says, "There are a lot of other places to save weight." Let's just assume that I have taken those into account and OUNCES matter on this build.

    Can anyone think of a reason that this will not work?
     
  2. J E Custom

    J E Custom Well-Known Member

    Messages:
    7,313
    Joined:
    Jul 29, 2004


    There is no problem if it is the thread protector that replaces the muzzle break.

    I would recommend the 7071 grade of aluminum for strength.

    J E CUSTOM
     

  3. sinarms

    sinarms Well-Known Member

    Messages:
    322
    Joined:
    Oct 24, 2010
    You can always give it a try to see how it holds up. I would go with a smooth nut for strength and use a spanner wrench.
     
  4. redneckclimbing

    redneckclimbing Well-Known Member

    Messages:
    240
    Joined:
    Jan 24, 2012

    J E-

    It will be the barrel nut that holds the barrel in place. Do you see any problems with that? I was thinking the same as fas as material, 7071 T6 Al.
     
  5. msalm

    msalm Well-Known Member

    Messages:
    225
    Joined:
    Jul 18, 2007
    Since it only acts as a jam nut it should work, but it may not too. AR's use em' and although not the same design, it's essentially the same thing.
     
  6. J E Custom

    J E Custom Well-Known Member

    Messages:
    7,313
    Joined:
    Jul 29, 2004


    I think I would use stainless or Chrome Moly for the barrel nut because of the thread strength and the same coefficient of expansion as the barrel and the action. (Heating and cooling could cause the
    nut to loosen)

    There are less critical areas to shed weight (Scopes weigh 1 and 1/2 to 3 pounds difference and would be a better place to save weight IMO.

    Just my opinion. Better to be safe than sorry.

    J E CUSTOM
     
  7. royinidaho

    royinidaho Writers Guild

    Messages:
    8,853
    Joined:
    Jan 20, 2004
    J E,

    You are spot on but too soft in your words. It's flat a bad idea!

    The temperature coefficient difference between barrel/action and nut is significant.

    Why would one want to barrel nut a Rem action anyway? If a switch bbl setup is the goal, I see no problem with going nut less. The bbl doesn't have to be "that" tight. Use your personal definition of "that"...
     
  8. Clark

    Clark Well-Known Member

    Messages:
    655
    Joined:
    Oct 19, 2006
    An Aluminium barrel nut could work very well or very poorly.
    The devil is in the details.
    You would need to show a dimensioned sketch.

    Here are 3 examples of simple sketches.
     
  9. redneckclimbing

    redneckclimbing Well-Known Member

    Messages:
    240
    Joined:
    Jan 24, 2012

    The main reason for barrel nutting a Rem is to loose weight in the barrel and still maintain a descent muzzle diameter.

    For example a "light Palma" contour barrel will have a shank that is approx. 1.2" for three inches. Instead of with the barrel nut just 1.06 for that same three inches and then tapering from there. Saving you a few ounces with out giving up muzzle diameter.

    The coefficeint of thermal expansion with steel and AL are quite different although these numbers are based on the temperature of the metal itself. With the steel being heated from the inside out and and that heat being disappated through the rest of the barrel and receiver steel. Within resonable proximity. Then heating the Al at any given time the temperature of the Al is going to be less. Also Al looses heat faster helping it to maintain a cooler temperature.

    I would have to do the numbers to be sure but I would think that they would almost remain at their ambient temperature dimensions even with some fairly extended firing.

    JE-

    Thinking about it a little more you could be right. You would probably only save at most an ounce (just guessing) and maybe that wouldn't be worth it. I am going to barrel nut this next Rem regardless. So, if I have time maybe I will make an Al nut and let everyone know it works.

    P.S. Has anyone actually done this before?
     
  10. CA48

    CA48 Well-Known Member

    Messages:
    573
    Joined:
    Nov 18, 2009
    Just a thought here, feel free to tell me if I'm off but
    why not go with titanium.
     
  11. Clark

    Clark Well-Known Member

    Messages:
    655
    Joined:
    Oct 19, 2006
    The expansion of Aluminium is 12.3 10-6 in/in oF
    The expansion of steel is 7.3 10-6 in/in oF

    If I am doing this right, to get 1% difference in expansion, we would need to change the temp 2000 oF.
     
  12. redneckclimbing

    redneckclimbing Well-Known Member

    Messages:
    240
    Joined:
    Jan 24, 2012
    I believe those are linear expansion numbers but, you do make a point. Stuff really has to heat up to grow enough to get loose. That, combined with it just being a jam nut, makes me think it would work.

    Ti would be a very strong option except that it is heavier than Al and is especially hard to machine, (from what I've heard).

    With an Al nut 1.30" in diameter and an internal diameter of 1.0" and being .75" long you would save 2.3 oz over a steel barrel nut of the same dimensions.

    So, if you barrel nut a Rem action as disucssed earlier you only save about 1.2 oz. with a steel barrel nut. However, with the Al nut you would save about 3.5 oz.

    Some people might say that's not worth it but if you figure that a pair of two piece Talley bases weigh about 2 ozs., that might make you think.
     
  13. Clark

    Clark Well-Known Member

    Messages:
    655
    Joined:
    Oct 19, 2006
    Trying to organize a group of engineers, I told them that area savings on a military printed wiring board was worth $10 parts price difference per square inch, except along a heat sink where we would give $100.

    Likewise on the rifle weight savings, an Aluminium PAWS trigger guard saved weight at a cost of $10 per ounce over the stock steel part
    P.A.W.S. at Brownells
     
  14. J E Custom

    J E Custom Well-Known Member

    Messages:
    7,313
    Joined:
    Jul 29, 2004


    Thinking outside of the box is always good if you have a single objective in mind (Weight for
    example). It breeds innovation but it can also just be a bad idea.

    A ultra light rifle has many attributes for carrying and short distance hunting, But from a accuracy
    point they are more difficult for the marksman to use at extended distances. (Not as steady and
    much more finicky in load development) they can be very accurate under perfect conditions and
    positions, (But how often are perfect conditions present while hunting).

    Dissimilar metals have a way of causing problems and mixing Aluminum and steel is problematic
    and may cause problems. (I once had a 30/378 built on a chrome Molly action, I decided to replace
    the action screws with stainless because the factory ones were slot head screws and harder to
    torque than the Allen head screws I had.)

    Every 8 to 10 shots accuracy would fall off and after checking the torque the screws had loosened.
    not believing that the problem was stainless to chrome Molly, I switched back to the steel slot
    head screws, end of problem. Later I found some Allen head screws in steel and they are still on
    the rifle.

    I also don't like the aluminum scope bases and rings because of there strength.Almost without
    exception, every failure has been while hunting and I just don't take the chance any more.

    I seem to learn my lessons the hard way so I have become very conservative.

    Just some recommendations.

    J E CUSTOM