AR-15 5.56 vs .223 chambering

Merlinnv12

January 19, 2020 23:18

What is the difference between the two cartridges? How is it that some AR’s can shoot both while some are limited to one or the other? 

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  Merlinnv12

  January 19, 2020 23:53

  Thanks. That explains a lot. 

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  varian

  January 20, 2020 01:16

  but that doesnt address the gabillions of 5.56 marked rounds that have the 55gr bullet loaded.  are they also loaded to a higher pressure standard.  and yes i do adhere to the rule of only shooting the round the barrel is marked for, unless you know positively otherwise.

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  Horse Plains Drifter

  January 20, 2020 03:24

  For that reason, every AR I buy is 5.56.

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  gruntled2

  January 20, 2020 08:48

  Just remember 2 goes into 5 but 5 doesn'5 go into 2. Too bad the same rule doesn't also work for 7.62 & .308 then it would be easier to remember. In both cases the civilian round will go in the NATO standard but not the other way around.

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  Mobuck

  January 20, 2020 12:56

  I have ONE .223 rifle that requires the use of a cleaning rod dropped down the barrel from the muzzle to remove fired cases from standard 5.56 loads. After finding this to be consistent, I no longer allow 5.56 ammo to be fired in this rifle. With a variety of 5.56/.223/.223 Wylde chambers in use, I've only found a problem with this single specimen. Combination of tight chamber and short leade is the suspected culprit. 

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  nmyers

  January 20, 2020 20:39

  Colt & RRA both describe in print that their modern sporting rifles can handle either round interchangeably.  Most of the others don't say, but I haven't seen any problems.  But, I've seen the problem Mobuck describes with a .223 bolt action; I'm guessing that they made the rifle to be as accurate as possible with the listed round, which is to be commended.
  

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  Mr. Perfect

  January 20, 2020 20:42

  gruntled2 said:

  Just remember 2 goes into 5 but 5 doesn'5 go into 2. Too bad the same rule doesn't also work for 7.62 & .308 then it would be easier to remember. In both cases the civilian round will go in the NATO standard but not the other way around.

  
  Yup
  

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  KenK/84Bravo

  January 20, 2020 20:47

  I honestly do not know why anyone would purchase an AR in .223 vs. 5.56, unless they just did not know any better. This particular question was a common question I fielded at my last job. I was "the Gun Guy."

  
  

  Why limit yourself, or your ammunition selection?

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