Ar barrel length

Discussion in 'General Rifle Discussion' started by bushmaster74, Jun 12, 2014.

  1. bushmaster74

    bushmaster74 New Member

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    Wanting to do a barrel change on my cmmg. Was wanting to put on a 24" heavy barrel. What's the pros and cons of going that long. I like the look mainly but still want accuracy.


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  2. fa35jsf

    fa35jsf New Member

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    Well as it was mentioned a few days ago on another thread, a longer barrel does not necessarily mean greater accuracy. However, a longer barrel will mean faster muzzle velocities which translates into less drop and more energy at distance. According to this calculator with a 55gr bullet and an initial velocity of 3000fps, the increase in velocity from 16 to a 24 inch barrel is 230 fps.

    http://shootersnotes.com/Velinfo.php
     
    Last edited: Jun 13, 2014

  3. fa35jsf

    fa35jsf New Member

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    And so by Hornady's online tool, the 230fps increase will decrease the drop at 300 yards by 2.5 inches, 500 yards by 11.2 inches, and at 700 yards by a whopping 31.8 inches using the same bullet and powder. The above numbers are the result of this equation (24 inch barrel velocity - 16 inch barrel velocity). Remember that the actual drop is still quite great at those distances.
     
    Last edited: Jun 13, 2014
  4. kbd512

    kbd512 Well-Known Member Lifetime Supporter

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    The "pro" is that you like way the rifle looks.

    The "con" is that the rifle is now as long as a battle rifle, it weighs as much as a battle rifle with worse weight distribution, and the velocity loss between 24 and 20 inches is minimal.

    But hey, it's your money and ultimately you are the one who will be happy or unhappy. I'd say it may be useful as a moderate distance target rifle or perhaps open terrain hunting rifle, if your locale allows 5.56MM for hunting, and it squeezes every last ounce of juice outta the 5.56MM, but that's about it.
     
  5. bushmaster74

    bushmaster74 New Member

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    I'm kinda goin for a bench rest / bipod rifle with this one. I know the longer / heavier barrel won't be a comfortable shouldered rifle Just kinda goin for look but shill want it too shoot good


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  6. Highpower

    Highpower New Member

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    I was with you there until I got to feet per minute.... ;)

    It was a test to see if we're paying attention, right? :D
     
  7. fa35jsf

    fa35jsf New Member

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    HAHA. Hey I was tired and just got done calculating fuel flow in pounds per minute.
     
  8. bushmaster74

    bushmaster74 New Member

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    As far as looking like a battle rifle and heavy I don't mind. But it should still shoot fine right? On shelf ammo?


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  9. Werminator

    Werminator Member

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    Bush, you will still have to find the right load for ultimate accuracy. Keep in mind also that every gun and every barrel is an individual and as such won't react equitably to all cartridges. Try several different loads methodically so as to find what load your weapon places on target most consistenly and base your results on that loading.
     
  10. Sniper03

    Sniper03 Supporting Member Supporter

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    Bushmaster,

    From experience, I would only recommend a 20" max length heavy varmint barrel for your rifle. The 24 is very front heavy. The other issue is it makes the rifle entirely too heavy to pack around incase you want to use it for something else other than stationary on a bench. Like for instance varmint or predator hunting. In addition it will shoot no better than the 20". I have had two Rock River Arms 20" A-4 Varmint Rifles both were 1/4 MOA guns when I was having a good day. Bottom line the 24 will do no better and heavy as stated. So my advise if you are going to go to a Heavy Barrel only go to the 20" even for bench shooting. Of course the quality of the barrel is important as well as selecting the barrel twist for the rounds you will be shooting. Mine were both 1:8 Twist Stainles Air Guaged Wildy Chambers. I mostly shot 55 gr. match bullets out of them but the 1:8 will also shoot well with heavier bullets like 62-69 grain rounds. While the 1:12 twist can only handle rounds 55 gr and lighter. The Rock River Barrels are Wilson Barrel Company barrels. There are many good barrel companies but the Rock River/Wilsons are fine barrels proven by the groups they consistantly produce.
    Good luck on your choice!:)

    03
     
  11. sfcjcl

    sfcjcl New Member

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    I picked up a DPMS Panther 24SS for $940.00 during the great craze of 2012/13. I only shoot match grade .223 (Black Hills 77 grain) with a 3/4" grouping at 600m consistantly. I'm want to work out to 800m with a sub 1 inch group,but I am handicaped by making stupid mistakes most of the time.

    I purchased this rifle at the PX here at Fort Bliss. Now, I don't want to talk bad about these people, but when I purchased this rifle with three others on 18 Dec 2012, there was about 100 people crowding around the Gun counter and it took over four hours for my background check to come back. When I finally got a clerk to help me, I had already picked out what I wanted, yet asked if there was anything else back behind the counter. Got shown the DPMS and was told it was a 20". I and my battle thought it look mighty long for 20", but took the clerks word for it and I added it to my collection. It wasn't til I got it home that I realized (and measured) that it was a 24".

    I agree with the other post that 20" is optimal, but don't think that the other 4" hurt in overall performance. Yet, lugging that sucker around is a b***h.
     
  12. CaseyChadwell

    CaseyChadwell New Member

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    3/4" at 600m??? Or 3/4 moa?
     
  13. ctshooter

    ctshooter New Member

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    I'm saying 3/4 moa. 3/4" at 600 with 5.56 would be simply amazing!
     
  14. JonM

    JonM Moderator

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    20" is the max i would go. its what i used in my precision build. while you get a slight bit of velocity you do not get any practical distance increase at max range. 223/556 is a 600 yard cartridge thats it.

    20" krieger with extra long jp handguard

    [​IMG]

    any longer and the weight does funky things to the reciever.

    even in a bolt gun the 223 is not very practical longer than 20"

    if i had to do over i would have ordered a 18" barrel.
     
  15. CaseyChadwell

    CaseyChadwell New Member

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    I'm looking for a good HBar upper with a 18" barrel for my PSA lower I just picked up.
     
  16. CaseyChadwell

    CaseyChadwell New Member

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    I'd go 20" if I could find someone to trade me my collapsible stock for a fixed stock.
     
  17. bushmaster74

    bushmaster74 New Member

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    was looking at a stag arms barrel any feedback on quality? also if i were to go to 24 in would have tp be pickier on ammo or will it still shoot the cheaper stuff just with a little less accuracy
     
  18. Sniper03

    Sniper03 Supporting Member Supporter

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    bushmaster,

    First of all Stag makes good stuff also. I think they do use some Shaw Barrels on some of their rifles? Call them and ask if you like their product.
    But if you are wanting peak accuracy as was reflected in your earlier posts the cheap stuff is not going to do it! But just for plinking and having fun OK! For Matches NO!
    If I were going to buy the upper you are talking about I would prefer it be a Wilson Barrel not to be confused with Wilson Combat. They are not the same company as some get that mixed up. If you buy just ask the company what barrel it has. I know Rock River uses Wilson almost exclusively. I am sure others do as well and some of the members here can probably tell you who they are. But once again I am telling you the 20" is probably the better all around choice. They shoot 600 yard matches at Camp Perry Ohio with 20" National Match barrels which are not Bull or Varmint sized barrels. So a 20" as many of us has advises is more than what you need for precise accuracy and performance. Most Bench Matches are fired at 100 or 200 yards anyway. JonM has also given you some great advise as well as others.

    03
     
  19. sfcjcl

    sfcjcl New Member

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    Thank You for the correction....Im on the last hours of a very long Brigade Staff Duty stint and my mind is going to mush.

    Yes, 3/4 MOA at 600MM