AR15 buffer tube length

BillOrr

October 08, 2011 11:07

I am building my first AR and am a little confused about buffer tube length. I have a Daniel Defense upper with a 16 inch barrel and a mid-length gas blow-back system. The stock will be a Magpul CTR.

So far all I have been able to find as far as buffer tube lengths are "rifle" and "carbine".

Do I use one of these sizes or am I missing a mid-length tube somewhere? Does the length of the operating system have anything to do with the buffer tube length?

Also: any recommendations on buffer tube kits or sites that have quality products? I was looking at a bushmaster kit from ebay but would rather spend more and get something that will do me right. Would it be even more prudent to get it one piece at a time?

I appreciate your time and input guys, Thanks in advance.

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  rufe-snow

  October 08, 2011 11:36

  According to the Midway catalog, the Magpul CTR buttstock. "Requires the use of a carbine length buffer tube".
  
  I would contact Midway for their AR 15 catalog. It's provided free under the title. "Gunsmithing The tools of the Trade". In my experience Midway has some of the best prices and selection of AR 15 parts available.

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  armilite

  October 08, 2011 12:25

  quote:Originally posted by rufe-snow
  According to the Midway catalog, the Magpul CTR buttstock. "Requires the use of a carbine length buffer tube".
  
  I would contact Midway for their AR 15 catalog. It's provided free under the title. "Gunsmithing The tools of the Trade". In my experience Midway has some of the best prices and selection of AR 15 parts available.
  
  
  
  Now the question that should be asked is if it is a Mil-Spec buffer tube or a Commercial ??? as there is a difference.

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  rufe-snow

  October 08, 2011 12:36

  quote:Originally posted by armilite
  
  
  
  Now the question that should be asked is if it is a Mil-Spec buffer tube or a Commercial ??? as there is a difference.
  
  
  
  It strikes me that it would be best to contact Magpul regarding this, as it's their stock. Obviously they would have the best knowledge of what would be the best carbine length buffer tube to use in their stock.

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  Txs

  October 09, 2011 11:40

  quote:Originally posted by rufe-snow
  quote:Originally posted by armilite
  
  
  
  Now the question that should be asked is if it is a Mil-Spec buffer tube or a Commercial ??? as there is a difference.
  
  
  
  It strikes me that it would be best to contact Magpul regarding this, as it's their stock. Obviously they would have the best knowledge of what would be the best carbine length buffer tube to use in their stock.
  The MagPul CTR is available in either commercial or milspec dimensions.
  
  Many people have used 'commercial' receiver extensions on their rifles with no problems, but due to dimensional as well as thread design differences the milspec type is unarguably the stronger of the two.
  
  The price differences aren't that great, so when selecting components for an AR build it makes little sense to choose to go with the weaker design.

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  sandwarrior

  October 10, 2011 06:09

  quote:Originally posted by armilite
  quote:Originally posted by rufe-snow
  According to the Midway catalog, the Magpul CTR buttstock. "Requires the use of a carbine length buffer tube".
  
  I would contact Midway for their AR 15 catalog. It's provided free under the title. "Gunsmithing The tools of the Trade". In my experience Midway has some of the best prices and selection of AR 15 parts available.
  
  
  
  Now the question that should be asked is if it is a Mil-Spec buffer tube or a Commercial ??? as there is a difference.
  
  
  What exactly Nevermind, here are the "differences'.
  
  http://cdn.magpul.com/downloads/Receiver_Extension_Commercial_M4.pdf
  
  http://cdn.magpul.com/downloads/Receiver_Extension_Milspec_M4.pdf

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  tsr1965

  October 10, 2011 07:22

  quote:Originally posted by Txs
  quote:Originally posted by rufe-snow
  quote:Originally posted by armilite
  
  
  
  Now the question that should be asked is if it is a Mil-Spec buffer tube or a Commercial ??? as there is a difference.
  
  
  
  It strikes me that it would be best to contact Magpul regarding this, as it's their stock. Obviously they would have the best knowledge of what would be the best carbine length buffer tube to use in their stock.
  The MagPul CTR is available in either commercial or milspec dimensions.
  
  Many people have used 'commercial' receiver extensions on their rifles with no problems, but due to dimensional as well as thread design differences the milspec type is unarguably the stronger of the two.
  
  The price differences aren't that great, so when selecting components for an AR build it makes little sense to choose to go with the weaker design.
  
  
  The threads are the same, as they thread into the same reciever...right? How can they be differrent? If they were different, then they would be stronger on the commercial buffer tube, as it has 0.010" thicker walls, which would mean more meat on the threads. Just because it is for Uncle Sam, does not mean it is the best.
  
  Yes, I do understand that the commercial spec can vary all over the place where it wants to. Even to the point where the buffer tube would be thinner than the mil-spec. However, the OP asked about a specific buffer tube/stock set.
  
  Best
  
  EDIT 1
  
  Txs,
  
  Thanks for the info. I am a firm believer that I can learn something new every day. That lesson was greatly appreciated. Thanks.
  
  Best

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  Txs

  October 10, 2011 10:14

  quote:Originally posted by tsr1965
  The threads are the same, as they thread into the same reciever...right? How can they be differrent? If they were different, then they would be stronger on the commercial buffer tube, as it has 0.010" thicker walls, which would mean more meat on the threads.
  
  Yes, I do understand that the commercial spec can vary all over the place where it wants to. Even to the point where the buffer tube would be thinner than the mil-spec. However, the OP asked about a specific buffer tube/stock set.Milspec style tubes begin with a thicker forward section and the threading is cut into this raised portion of the tube.
  
  Commercial types are a simple straight walled tube of consistent thickness and the threading is cut down into the tube wall itself. In other words, the tube's walls are thinned at precisely where it's inserted into the lower receiver. It's less expensive to manufacture this type, but it it has the efffect of creating a shear line for the buttstock.
  
  Range gun/light duty user requirements can be met with this corner cutting design standard that saves a few dollars on a build, but don't be fooled into thinking there's no strength advantage to the milspec design.
  
  
  
  

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  sandwarrior

  October 10, 2011 13:04

  TXS,
  
  Don't forget the mil-spec is made of 7075-T6 and the commercial version is made of 6061-T6. At least for Magpul. The commercial version can probably be made from any aluminum compound they feel is strong enough to take the abuse it's going to get.
  
  P.S. -Outstanding example on how that works.

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  cpermd

  October 10, 2011 16:56

  The mid length gas system has nothing to do with buffer tube length.
  
  You will need a carbine length buffer tube.
  
  CP

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  BillOrr

  October 11, 2011 08:09

  Thanks so much everyone. I learned a lot.
  
  There is such an abundance of knowledge on these forums... it's amazing what info one can pick up in a matter of days from one simple question.

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  BillOrr

  October 11, 2011 08:13

  CP: that was the answer I was looking for. Thanks

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